ANIMAL LIFE IN THE YOSEMITE
UNIVERSITY OF CALIFORNIA
[GRINNELL-STORER] PLATE 1
SlKKKA XkVAIiA 1\(ISV l''l.\('ll
ANIMAL LIFE IN THE YOSEMITE
AN ACCOUNT OF THE MAMMALS, BIRDS,
REPTILES, AND AMPHIBIANS IN
A CROSS-SECTION OF THE
SIERRA NEVADA
BY JOSEPH GRINNELL
AND
TRACY IRWIN STORER
Contribution from the Museum of Vertebrate Zoology University of California
UNIVERSITY OF CALIFORNIA PRESS
BERKELEY, CALIFORNIA
1924
Copyright, 1924
BY
University of California
Museum of Vertebrate Zoology
J. Grinnell, Director
Issued AprU 17, 1924
PREFACE
The national parks of America render as their most important seiTice a full free opportunity to all who will to find in them a complete recreation, physical, mental, esthetic. In performing this service the animal life existing within their borders constitutes a valuable asset. For the best recreative forces in nature are those which ser\'e most quickly to call into play latent or seldom used faculties of mind and body whose exercise tends to restore to normal balance the human mechanism that has been disturbed by special or artificial conditions of living. Foremost among these forces are the living things that move and utter sounds, exhibit color and changing form, and by these qualities readily attract and fix our interest. To seek acquaintance with those primal objects of interest is to know the joy of vigorous muscular activity; better still, it is to realize the pos- session of the generally neglected senses of far-seeing and far-hearing, and to invite an esthetic appeal of the highest type and an intellectual stimulus of infinite resource.
Of the thousands who each year visit the Yosemite Valley and its environs, a certain proportion are already interested in natural history; and anyone who leaves the region without gathering some definite knowledge of its natural history has failed to get adequate gain from his opportunities. The geology, topography, and botany of the Yosemite have been studied with some care; and there are instructive and stimulating manuals available dealing with these subjects. But heretofore only a few brief accounts have appeared in print concerning the bird life of the region, and practically nothing has been made available regarding its mammals, reptiles, and amphibians. It was in an effort to supply this deficiency that a survey of the vertebrate natural history of the Yosemite region was under- taken by the California Museum of Vertebrate Zoology. The present volume deals with the results of that survey.
The principal objects in view in undertaking the survey were: To find out what species of mammals, birds, reptiles, and amphibians exist, or have within modern times existed, in the circumscribed area selected for study; to learn as much as possible concerning the local distribution of each of these species, and to map out the general life areas within the region; to learn as much as time permitted of the food relations, the breeding habits, and the behavior, individually, of each of the species; and finally to put all this information on permanent record, in a form accessible to, and generally assimilable by, the public, both lay an<l scientific.
In attempting the achievement of this last aim the authors have brought together their materials with every precaution to insure accuracy of fact and correctness of inference. No sacrifice of precision has been made consciously with the end merely of affording 'attractive reading.' At the same time, technical terms, where the same ideas could be expressed in words familiar to every reader of fair education, have been avoided. Ideally, we have tried to present our science, perfectly good science, in straightforward, readable form.
Joseph Grinnell. Tracy Irwix Storer. Berkeley, July 6, 1922.
[V]
ACKNOWLEDGMENTS
The Museum of Vertebrate Zoology is under obligation to numerous persons and organizations for support and assistance in the prosecution of the Yoscmite survey. The greatest aid from any one source has come from Miss Annie M. Alexander, who made the enterprise possible through her unstinted financial support of the Museum during the several years in which the field and office work has been under way. Her unswerving faith in the worthiness of the undertaking served continually to encourage and energize those who were concerned with its conduct.
When the plan was first outlined it was put before Dr. William F. Bad^, then President of the Sierra Club. Its merits and feasibility were enthusiastically endorsed by him and subsequently by the Sierra Club formally. This endorsement went far toward bringing the enterprise to the favorable attention of the people in Washington and in Yosemite Valley, to whom we later found it needful to appeal for material help of various kinds.
Mr. Stephen T. Mather, Director of National Parks, besides personally con- tributing to the fund for field work, has rendered aid in other ways. Financial help, at a time when this was most needed, was received also from Mr. George W. Marston of San Diego and from Mr. James D. Phelan of San Francisco.
The National Park Service of the Federal Government granted the special permits necessary for the taking of specimens within the boundaries of the Yosemite National Park. Many of the local employees of the same Service ren- dered valuable aid. To Mr. Gabriel Souvelewsky, then Supervisor of Yosemite Park, we owe grateful acknowledgment for immediate and practically expressed interest in our program of field work in the winter of 1914-15. Among others in the Valley who have helped us materially we may mention in particular Messrs. W. B. Lewis, E. P. Leavitt, Forest S. Townsley, Ansel F. Hall, Charles C. Bull, Charles W. Michael, N. L. Guiberson, and the late George W. Bell. Information on specific and general questions has been freely furnished by these men, and many valuable specimens have been secured through them for the Museum of Vertebrate Zoology. Many of the organizations engaged in business connected with Yosemite Valley aided our enterprise by granting special privileges. Among these are to be named the Yosemite Valley Railroad Company, The Yosemite Transportation Company, The Sentinel Hotel, and The Curry Camping Company. The Sierra Club, during the field season of 1915, gave us the use of their pack train.
The colored and wash drawings used for illustrating the present volume were executed by Major Allan Brooks upon the basis of Yosemite materials. The skill of Mrs. Frieda L. Abernathy was very helpful in preparing the line drawings. The photographs used were taken in course of our regular field work except four whose outside sources are acknowledged in their respective captions. To Professor Oliver M, Washburn, Manager of the University of California Press, we are indebted for important help in assembling the illustrations that appear in this book. And to Mr. Joseph W. Flinn, Superintendent of the University Printing Office, we hereby express our appreciation of his personal interest in guiding the work through the press.
[vi]
The United States Bureau of Plant Industry and the University of California Division of Forestry aided in the determination of seeds found in the cheek pouches of chipmunks. The United States Bureau of Biological Survey determined the crop and gizzard contents of a number of birds. Dr. Harvey M. Hall identified numerous plants submitted to him.
Much information and many vertebrate specimens have been obtained from Mr. Donald D. McLean, whose home is at Dudley, on Smith Creek, six miles (air- line) east of the town of Coulterville. Mr. McLean's parents and uncle, Mr. and Mrs. John L. McLean and Mr. Walter Dudley, also aided us in many ways while field work was going on in their neighborhood.
[vii]
CONTENTS
PAGE
List of plates, colored xv
List of plates, half-tone xvi
List of text figures xvii
Introduction 1
Distribution of animal life in the Yosemite section 4
Table of occurrence, according to life zone, of the mammals, breeding birds, reptiles,
and amphibians of the Yosemite section 14
Censuses of birds in the Yosemite section 22
The interrelations of living things 36
Scope of the species accounts 40
The Mammals 43
Moles, Scapanus latimanus 43
Yosemite Mole, Scapanus latimanus sericatus
San Joaquin Mole, Scapanus latimanus campi
Mono Mole, Scapanus latimanus monoensis Shrews, Genus Sorex • 47
Dusky Shrew, Sorex obscurus obscurus
Adorned Shrew, Sorex ornatus
Yosemite Shrew, Sorex montereyensis mariposae
Sierra Nevada Shrew, Sorex vagrans amoenus
Lycll Shrew, Sorex lyelli
Navigator Shrew, Neosorex palustris navigator 50
Little California Bat, Myotis californicus californicus 51
High Sierra Bat, Myotis lucifugus altipetens 55
Long-legged Bat, Myotis longicrus longicrus 56
Fringed Bat, Myotis thysanodes 57
Merriam Bat, Pipistrellus hesperus merriami 57
Large Brown Bat, Eptesicus fuscus 58
Hoary Bat, Nyctcris cincrea 59
Pacific Pallid Bat, Antrozous pacificus '. 60
Mexican Free-tailed Bat, Nyctinomus mexicanus 61
American Black Bear, Ursus americanus 63
Grizzly Bear, Ursus henshawi 68
Mountain Coyote, Canis latrans lestes 71
Cascade Red Fox, Vulpes cascadensis 77
San Joaquin Kit Fox, Vulpes macrotis mutica 77
California Gray Fox, Urocyon cinerooargentous californicus 78
California Ring-tailed Cat, Bassariscus astutus raptor 81
California Coon, Procyon lotor psora 81
Sierra Pine Marten, Martes caurina sierrae 82
Pacific Fisher, Martos pcnnanti pacifica 83
Sierra Nevada Wolverine, Gulo luscus luteus 85
Mountain Weasel, Mustela arizonensis 86
Sierra Least Weasel, Mustela muricus 89
Pacific Mink, Mustela vison cnergumenos 89
[ viii ]
PAGE
California Spotted Skunk, Spilogale phenax phenax .' 90
Striped Skunk, Mephitis occidentalis 91
California Badger, Taxidea taxus neglecta 92
Northwestern Mountain Lion, FeHs oregonensis oregonensis 95
CaUfornia Wildcat, Lynx eremicus californicus 99
House Mouse, Mus musculus 101
Alexandrine Rat, Rattus rattus alexandrinus 103
Common White-footed Mice, Peromyscus maniculatus 104
Gambel White-footed Mouse, Peromyscus maniculatus gambeli
Sonora White-footed Mouse, Peromyscus maniculatus sonoriensis
Boyle White-footed Mouse, Peromyscus boyhi boylii 110
Big-eared White-footed Mice, Peromyscus truei Ill
Gilbert White-footed Mouse, Peromyscus truei gilberti
True White-footed Mouse, Peromyscus truei truei
Parasitic White-footed Mouse, Peromyscus californicus californicus 112
Short-tailed Grasshopper Mouse, Onychomys leucogaster brevicaudus 113
Long-tailed Harvest Mouse, Reithrodontomys megalotis longicauda 114
Streator Wood Rat, Neotoma fuscipes streatori 116
Gray Bushy-tailed Wood Rat, Neotoma cinerea cinerea 120
Yosemite Meadow Mouse, Microtus montanus yosemite 122
California Meadow Mice, Microtus californicus 126
Tule Meadow Mouse, Microtus californicus aestuarinus
Mariposa Meadow Mouse, Microtus caUfornicus mariposae
Sierra Cantankerous Meadow Mouse, Microtus mordax sierrae 129
Short-tailed Meadow Mouse, Lagurus curtatus 133
Mountain Lemming Mouse, Phenacomys orophilus 133
Pocket Gophers, Genus Thomomys 134
Fresno Pocket Gopher, Thomomys bottae pascalis
Digger Pine Pocket Gopher, Thomomys bottae mewa
Yosemite Pocket Gopher, Thomomys alpinus awahnee
Sierra Nevada Pocket Gopher, Thomomys monticola monticola
Fisher Pocket Gopher, Thomomys quadratus fisheri Pocket Mice, Genus Perognathus 144
California Pocket Mouse, Perognathus californicus californicus
San Joaquin Pocket Mouse, Perognathus inornatus inornatus
Great Basin Pocket Mouse, Perognathus parvus olivaceus Kangaroo Rats, Genus Dipodomys 146
Heermann Kangaroo Rat, Dipodomys heermanni heermanni
Merced Kangaroo Rat, Dipodomys heermanni dixoni
Pale-faced Kangaroo Rat, Dipodomys leucogenys
Mono Kangaroo Mouse, Microdipodops polionotus 149
Allen Jumping Mouse, Zapus pacificus alleni 149
Yellow-haired Porcupine, Erethizon epixanthum epixanthum 151
Sierra Mountain Beaver, Aplodontia rufa caUfornica. 155
Southern Sierra Marmot, Marmota flaviventer sierrae 158
California Ground Squirrel, Citellus beecheyi beecheyi 162
Belding Ground Squirrel, Citellus beldingi 168
Stephens Soft-haired Ground Squirrel, Citellus mollis stephensi 173
Sierra Nevada Golden-mantled Ground Squirrel, Callospermophilus chrysodeirus
chrysodeirus 173
Tahoe Chipmunk, Eutamias speciosus frater 176
Allen Chipmunk, Eutamias senex 183
Mariposa Chipmunk, Eutamias merriami mariposae ;... 185
Long-eared Chipmunk, Eutamias quadrimaculatus 187
[ix]
PAGE
Alpine Chipmunk, Eutamias alpinus 190
Mono Chipmunk, Eutamias amoenus monoensis 194
Sagebrush Chipmunk, Eutamias pictus 195
CaUfornia Gray Squirrel, Sciurus griseus griseus 196
Sierra Chickaree, Sciurus douglasii albolimbatus 203
Sierra Flying Squirrel, Glaucomys sabrinus lascivus 211
Golden Beaver, Castor canadensis subauratus 215
Yosemite Cony, Ochotona schisticeps muiri 218
Black-tailed Jack Rabbits, Lepus californicus 221
California Jack Rabbit, Lepus californicus californicus
Desert Jack Rabbit, Lepus californicus deserticola
Sierra White-tailed Jack Rabbit, Lepus townsendii sierrae 224
Sacramento Cottontail, Sylvilagus audubonii audubonii 227
Washington Cottontail, Sylvilagus nuttallii nuttallii 227
Mariposa Brush Rabbit, Sylvilagus bachmani mariposae 228
Mule Deer, Odocoileus heraionus hemionus 231
Dwarf Elk, Cervus nannodes 241
Pronghorn Antelope, Antilocapra americana americana 242
Sierra Nevada Mountain Sheep, Ovis canadensis sierrae 243
The Birds 247
American Eared Grebe, Colymbus nigricollis californicus 247
Pied-billed Grebe, Podilymbus podiceps 248
California Gull, Larus californicus 248
Forster Tern, Sterna forsteri 251
Black Tern, Hydrochehdon nigra surinamensis 251
Farallon Cormorant, Phalacrocorax auritus albociliatus 251
Wliite Pehcan, Pelecanus erythrorh>Tichos 252
American Merganser, Mergus americanus 252
Mallard, -\nas platjThjTichos 253
Baldpate, Mareca americana 253
Cinnamon Teal, Querquedula cyanoptera 253
Shoveller, Spatula clypeata 254
Pintail, Dafila acuta 254
Harlequin Duck, Histrionicus histrionicus 255
American Bittern, Botaurus lentiginosus 256
Least Bittern, Ixobrychus exilis exilis 256
Great Blue Herons, Ardea herodias 256
California Great Blue Heron, Ardea herodias hyperonca
Palhd Great Blue Heron, Ardea herodias treganzai
Anthony Green Heron, Butorides virescens anthonyi 258
Black-crowned Night Heron, Nycticorax nycticorax naevius 259
Virginia Rail, Rallus virginianus 260
Mud-hen, FuUca americana .' 261
Northern Phalarope, Lobipes lobatus 261
Wilson Phalarope, Steganopus tricolor 262
Wilson Snipe, Gallinago delicata 263
Least Sandpiper, Pisobia minutilla 263
Spotted Sandpiper, Actitis macularia 263
Killdeer, Oxyechus vociferus vociferus 265
Mountain Quail, Oreortyx picta plumifera 267
Valley Quail, Lophortyx californica vallicola 270
Sierra Grouse, Dendragapus obscurus sierrae 272
Sage-hen, Centrocercus urophasianus 274
Band-tailed Pigeon, Columba fasciata fasciata 275
[X]
PAGE
Western Mourning Dove, Zenaidura macroura marginella 278
Turkey Vulture, Cathartes aura septentrionalis 279
White-tailed Kite, Elanus leucurus 281
Marsh Hawk, Circus hudsonius 281
Sharp-shinned Hawk, Accipiter velox 282
Cooper Hawk, Accipiter cooperi 284
Western Goshawk, Astur atricapillus striatulus 286
Western Red-tailed Hawk, Buteo boreaUs calurus 287
Red-bellied Hawk, Buteo lineatus elegans 289
Swainson Hawk, Buteo swainsoni 290
Ferruginous Rough-legged Hawk, Archibuteo ferrugineus 291
Golden Eagle, Aquila chrysaetos 292
Prairie Falcon, Falco mexicanus 294
Duck Hawk, Falco peregrinus anatum 294
Northern Pigeon Hawk, Falco columbarius columbarius 295
American Sparrow Hawk, Falco sparverius sparverius 296
American Osprey, Pandion haUaetus caroUnensis 297
Barn Owl, Tyto pratincola 298
Long-eared Owl, Asio wilsonianus 300
California Spotted Owl, Strix occidentalis occidentalis 304
Great Gray Owl, Scotiaptex nebulosa nebulosa 305
Saw-whet Owl, Cryptoglaux acadica 307
Southern California Screech Owl, Otus asio quercinus 308
Pacific Horned Owl, Bubo virginianus pacificus 309
Burrowing Owl, Speotyto cunicularia hypogaea 310
California Pigmy Owl, Glaucidium gnoma californicum 311
Road-runner, Geococcyx calif ornianus 313
Western Belted Kingfisher, Ceryle alcyon caurina 313
Modoc Woodpecker, Dryobates villosus orius 315
Willow Woodpecker, Dryobates pubescens turati 317
Nuttall Woodpecker, Dryobates nuttalli 319
Northern White-headed Woodpecker, Xenopicus albolarvatus albolarvatus 320
Arctic Three-toed Woodpecker, Picoides arcticus 326
Sierra Red-breasted Sapsucker, Sphyrapicus varius daggetti 327
Red-naped Sapsucker, Sphyrapicus varius nuchalis 330
WilHamson Sapsucker, Sphyrapicus thyroideus thyroideus 331
Northern Pileated Woodpecker, Phloeotomus pileatus abieticola 334
California Woodpecker, Melanerpes formicivorus bairdi 337
Lewis Woodpecker, Asyndesmus lewisi 341
Red-shafted Flicker, Colaptes cafer collaris 342
Poor-wills, Phalaenoptilus nuttalli 343
Dusky Poor-will, Phalaenoptilus nuttalli californicus
Nuttall Poor-will, Phalaenoptilus nuttalli nuttalli
Pacific Nighthawk, Chordeiles virginianus hesperis 346
Texas Nighthawk, Chordeiles acutipennis texensis 347
Northern Black Swift, Cypseloides niger borealis 349
Vaux Swift, Chaetura vauxi 35O
White-throated Swift, Aeronautes melanoleucus 351
Black-chinned Hummingbird, Archilochus alexandri 352
Anna Hummingbird, Calypte anna 353
Rufous Hummingbird, Selasphorus rufus 354
Allen Hummingbird, Selasphorus alleni 355
Calliope Hummingbird, Stellula calliope 356
Western Kingbird, TsTannus verticalis 359
[xi]
Ash-throated Flycatcher, Myiarchus cincrascens einerascens 360
Say Phoebe, Sayornis sayus ■ •••■• •*• 362
Black Phoebe, Sayornis nigricans .' ■.....-.....: ...• 362
Olive-sided Flycatcher, Nuttallornis borealis .-• - 364
Western Wood Pewee, Myiochanes richardsoni richardsoni — ... 365
Wright P\vcatcher, Empidonax wrighti ....- -. 367
Hammond Flycatcher, Empidonax hammondi .- ...:- 370
Traill Flycatcher, Empidonax trailli trailh 371
Western Flycatcher, Empidonax difficilis difficilis 372
Gray Flycatcher, Empidonax griseus 373
Horned Larks, Otocoris alpestris •- 374
Cahfornia Horned Lark, Otocoris alpestris actia
Dusky Horned Lark, Otocoris alpestris merrilU
Black-billed Magpie, Pica pica hudsonia 376
Blue-fronted Jay, Cyanocitta stelleri frontalis 379
Interior California Jay, Aphelocoma californica immanis 387
Woodhou.se Jay, Aphelocoma woodhousei 392
Western Raven, Corvus corax sinuatus 392
Western Crow, Corvus brachyrhynchos hesperis 392
Clark Nutcracker, Nucifraga columbiana 393
Pifion Jay, Cyanocephalus cyanocephalus 397
Cowbirds, Molothrus ater 398
Dwarf Cowbird, Molothrus ater obscurus
Nevada Cowbird, Molothrus ater artemisiae
Yellow-headed Blackbird, Xanthocephalus xanthocephalus 399
Red-winged Blackbirds, Agelaius phoeniceus 400
Bi-colored Red-winged Blackbird, Agelaius phoeniceus californicus
Nevada Red-winged Blackbird, Agelaius phoeniceus nevadensis
Kern Red-winged Blackbird, Agelaius phoeniceus aciculatus
Tri-colored Blackbird, Agelaius tricolor 407
Western Meadowlark, Sturnella neglecta 409
Bullock Oriole, Icterus buUocki 411
Brewer Blackbird, Euphagus cyanocephalus 413
California Evening Grosbeak, Hesperiphona vespertina californica 417
California Pine Grosbeak, Pinicola enucleator californica 419
California Purple Finch, Carpodacus purpureus californicus -120
Cassin Purple Finch, Carpodacus cassini 423
California Linnet, Carpodacus mexicanus frontalis 426
Sierra Crossbill, Loxia curvirostra bendirei 428
Sierra Nevada Rosy Finch, Leucosticte tephrocotis dawsoni 430
Willow Goldfinch, A.stragalinus tristis salicamans 434
Green-backed Goldfinch, Astragalinus psaltria hesperophilus 435
Lawrence Goldfinch, Astragalinus lawrencei 437
Pine Siskin, Spinus pinus pinus 438
English Sparrow, Passer domesticus 439
Vesper Sparrows, Pooecetes gramineus 440
Western Vesper Sparrow, Pooecetes gramineus confinis
Oregon Vesper Sparrow, Pooecetes gramineus affinis Savannah Sparrows, Pas.serculus sandwichcnsis 442
Aleutian Savannah Si)arrow, Pa.sserculus sandwichcnsis sinulwichensis
Western Savannah Sparrow, Pa.sserculus sandwichcnsis alaudiiuis
Nevada Savannah Sparrow, Passcrculus sandwiciiciisis nevadensis
Western Grasshopper Sparrow, Amiiiodrainus savannarum l)iinaculatus 443
Western Lark Sparrow, Chondestes grainmacus strigatus 444
[xii]
PAGE
White-crowned Sparrows, Zonotrichia leucophrys 446
Hudsonian White-crowned Sparrow, Zonotrichia leucophrys leucophrys
Intermediate White-crowned Sparrow, Zonotrichia leucophrys gambeli
Golden-crowned Sparrow, Zonotrichia coronata 450
Western Chipping Sparrow, Spizella passerina arizonae 452
Brewer Sparrow, Spizella breweri 456
Black-chinned Sparrow, Spizella atrogularis 458
Slate-colored Junco, Junco hyemalis hyemalis 458
Sierra Junco, Junco oreganus thui-beri 459
Shufeldt Junco, Junco oreganus shufeldti
Bell Sparrow, Amphispiza belli 464
Nevada Sage Sparrow, Amphispiza nevadensis nevadensis 466
Rufous-crowned Sparrow, Aimophila ruficeps ruficeps 467
Song Sparrows, Melospiza melodia 468
Modoc Song Sparrow, Melospiza melodia fisherella
Rusty Song Sparrow, Melospiza melodia rufina
Heermann Song Sparrow, Melospiza melodia heermanni
Merrill Song Sparrow, Melospiza melodia merrilli Lincoln Sparrows, Melospiza lincolni 470
Northeastern Lincoln Sparrow, Melospiza lincolni lincolni
Northwestern Lincoln Sparrow, Melospiza lincolni gracilis Fox Sparrows, Passerella iliaca 472
Shumagin Fox Sparrow, Passerella iliaca unalaschcensis
Kadiak Fox Sparrow, Passerella iliaca insularis
Valdez Fox Sparrow, Passerella iliaca sinuosa
Alberta Fox Sparrow, Passerella iliaca altivagans
Slate-colored Fox Sparrow, Passerella iliaca schistacea
Mariposa Fox Sparrow, Passerella iliaca mariposae
Mono Fox Sparrow, Passerella iliaca monoensis
Thick-billed Fox Sparrow, Passerella iliaca megarhyncha Spurred Towhees, Pipilo maculatus 477
Sacramento Spurred Towhee, Pipilo maculatus falcinellus
Nevada Spurred Towhee, Pipilo maculatus curtatus
Northern Brown Towhee, Pipilo crissalis carolae 480
Green-tailed Towhee, Oberholseria chlorura 482
Pacific Black-headed Grosbeak, Zamelodia melanocephala capitalis 484
California Blue Grosbeak, Guiraca caerulea salicarius... 490
Lazuli Bimting, Passerina amoena 491
Western Tanager, Piranga ludoviciana 493
Western Martin, Progne subis hesperia ; 497
Cliff Swallow, Petrochelidon lunifrons lunifrons 497
Barn Swallow, Hirundo erythrogaster erythrogaster 499
Tree Swallow, Iridoprocne bicolor 500
Northern Violet-green Swallow, Tachycineta thalassina lepida 501
Rough-winged Swallow, Stelgidopteryx serripennis 503
Bohemian Waxwing, Bombycilla garrula 604
Cedar Waxwing, Bombycilla cedrorum 504
Phainopepla, Phainopepla nitens 505
Shrikes, Lanius ludovicianus 506
California Shi-ike, Lanius ludovicianus gambeli
White-rumped Shrike, Lanius ludovicianus excubitorides
Western Warbling Vireo, Vireosylva gilva swainsoni 508
Cassin Vireo, Lanivireo solitarius cassini 511
Hutton Vireo, Vireo huttoni huttoni 513
[xiii]
PAGE
California Least Vireo, Vireo belli pusillus 514
Calaveras Warbler, Vermivora ruficapilla gutturalis 516
Orange-crowned Warblers, Vermivora celata 519
Lutescent Warbler, Vermivora celata lutescens
Rocky Mountain Orange-crowned Warbler, Vermivora celata orestera
California Yellow Warbler, Dendroica aestiva brewsteri 521
Alaska Myrtle Warbler, Dendroica coronata hooveri 523
Audubon Warbler, Dendroica auduboni auduboni 524
Black-throated Gray Warbler, Dendroica nigrescens 529
Townsend Warbler, Dendroica townsendi 531
Hermit Warbler, Dendroica occidentalis 532
Tolmie Warbler, Oporornis tolmiei. 534
Yellowthroats, Geothlypis trichas 538
Western Yellowthroat, Geothlypis trichas occidentaUs
Tule Yellowthroat, Geothlypis trichas scirpicola
Long-tailed Chat, Icteria virens longicauda 539
PUeolated Warblers, Wilsonia pusilla 540
Golden Pileolated Warbler, Wilsonia pusilla chryseola
Alaska Pileoated Warbler, Wilsonia pusilla pileolata
American Pipit, Anthus rubescens 542
American Dipper, Cinclus mexicanus unicolor 543
Sage Thrasher, Oreoscoptes montanus 546
Western Mockingbird, Mimus polyglottos leucopterus 547
California Thrasher, Toxostoma redivivura redivivum 548
Rock Wren, Salpinctes obsoletus obsoletus 550
Dotted Canon Wren, Catherpes mexicanus punctulatus 552
San Joaquin Bewick Wren, Thryomanes bewicki drymoecus 555
Western House Wren, Troglodytes aedon parkmani 556
Western Winter Wren, Nannus hiemalis pacificus 558
Western Marsh Wren, Telmatodytes palustris plesius 560
Sierra Creeper, Certhia familiaris zelotes 561
Slender-billed Nuthatch, Sitta carolinensis aculeata 564
Red-breasted Nuthatch, Sitta canadensis 568
Pigmy Nuthatch, Sitta pygmaea pygmaea 571
Plain Titmouse, Baeolophus inornatus inornatus 572
Short-tailed Mountain Chickadee, Penthestes gambeli abbreviatus 574
California Bush-tit, Psaltriparus minimus californicus 579
Lead-colored Bush-tit, Psaltriparus plumbeus 582
PaUid Wren-tit, Chamaea fasciata henshawi 582
Western Golden-crowned Kinglet, Regulus satrapa olivaceus 586
Western Ruby-crowned Kinglet, Regulus calendula cineraccus 589
Western Gnatcatcher, Polioptila caerulea obscura 593
Townsend Solitaire, Myadestes townsendi 595
Russet-backed Thrush, Hylocichla ustulata ustulata 600
Hermit Thrushes, Hylocichla guttata 602
Sierra Hermit Thrush, Hylocichla guttata sequoiensis
Alaska H(!rmit Thrush, Hylocichla guttata guttata
Dwarf Hermit Thrush, Hylocichla guttata nanus
Western Robin, Planesticus migratorius propinquus 605
Northern Varied Thrush, Ixoreus nacvius moruloides 614
Western Bluebird, Sialia mexicana occidentalis 615
Mountain Bluebird, Sialia cunucoidcs 622
fxiv]
PAGE
The Reptiles 626
Blue-bellied Lizards, Sceloporus occidentalis 626
Western Fence Lizard, Sceloporus occidentalis occidentalis
Pacific Blue-bellied Lizard, Sceloporus occidentalis bi-seriatus
Tenaya Blue-bellied Lizard, Sceloporus occidentalis taylori
Mountain Lizard, Sceloporus graciosus graciosus 628
California Horned Toad, Phrynosoma blainvillii frontale 630
Alligator Lizards, Genus Gerrhonotus 630
San Diego Alligator Lizard, Gerrhonotus scincicauda webbii
Sierra Alligator Lizard, Gerrhonotus palmeri
CaUfornia Whip-tailed Lizard, Cnemidophorus tigris mundus 632
Western Skink, Plestiodon skiltonianus 633
Rubber Snake, Charina bottae 635
Garter Snakes, Genus Thamnophis 636
Pacific Garter Snake, Thamnophis sirtalis infernalis
Giant Garter Snake, Thamnophis ordinoides couchii
Mountain Garter Snake, Thamnophis ordinoides elegans
Wandering Garter Snake, Thamnophis ordinoides vagrans
Western Ring-necked Snake, Diadophis amabilis amabilis 639
Coral King Snake, Lampropeltis multicincta 640
Boyle King Snake, Lampropeltis getulus boylii 640
California Striped Racer, Coluber lateralis 641
Western Yellow-bellied Racer, Coluber constrictor flaviventris 643
Valley Gopher Snake, Pituophis catenifer heermanni 643
Pacific Rattlesnake, Crotalus oreganus 645
Pacific Mud Turtle, Clemmys marmorata 650
The Amphibians 651
Pacific Coast Newt, Notophthalmus torosus 651
Mount Lyell Salamander, Eurycea platycephala 652
Arboreal Salamander, Aneides lugubris lugubris 653
Slender Salamander, Batrachoseps attenuatus 654
Western Spade-foot Toad, Scaphiopus hammondii hammondii 654
California Toad, Bufo boreas halophilus 655
Northwestern Toad, Bufo boreas boreas
Yosemite Toad, Bufo canorus P57
Pacific Tree-toad, Hyla regilla 661
Yellow-legged Frogs, Rana boylii 663
California Yellow-legged Frog, Rana boylii boylii
Sierra Yellow-legged Frog, Rana boylii sierrae
California Red-legged Frog, Rana aurora draytonii 666
Bibliography: Articles relating chiefly or importantly to the vertebrate animals of the Yosemite section, published up to the end of 1920 667
Index 743
Plates, Colored plate (scattered through the text)
1. Sierra Nevada Rosy Finch frontispiece
OPPOSITE PAGE
2. Sierra Golden-mantled and Belding ground squirrels; Marmot 158
3. Chipmunks of the Yosemite section 182
4. Band-tailed Pigeon 278
5. Woodpeckers of the Yosemite section 326
6. Family group of WilUamson Sapsuckers 334
[XV]
PLATE OPPOSITE PAGE
7. Cassin and California purple finches and California Linnet 422
8. Some sparrows of the Yosemite section 454
9. Warblers of the Yosemite section 518
10. Some small birds of the Yosemite forests 566
11. Townsend Solitaire and Russet-backed and Sierra Hermit thrushes 598
12. Coral King Snake; Western Skink, young and adult 630
Plates, Half-tone (in signatures at end of text) page
13. Merced River bottom near SncUing; blue oak in winter, with mistletoe 671
14. Digger pine association near Pleasant Valley; edge of yellow pine association three
miles east of Coulterville 673
15. Golden oak association near Rocky Point; south bank of Merced River near El
Portal 675
16. Yosemite Valley from Big Oak Flat road, with golden-oak talus in foreground;
meadow and cottonwood associations in Yosemite Valley 677
17. Jeffrey pine and huckleberry oak associations east of Half Dome; white fir associa-
tion near Chinquapin 679
18. Vogelsang Lake and Pass; Tuolumne Meadows 681
19. Mounts Gibbs and Dana from the east; Williams Butte near Mono Lake 683
20. Navigator, Yosemite and Dusky shrews 685
21. Bats of the Yosemite Valley and higher Sierra Nevada 687
22. Tracks of Black Bear in Yosemite Valley 689
23. Pacific Fisher, Sierra Pine Marten and Sierra Nevada Wolverine 690
24. California Badger and its work 691
25. Boyle and Common white-footed mice and House Mouse 692
26. Some "leaping" rodents of the Yosemite section 693
27. Yosemite Pocket Gopher and Yosemite Mole '■ 695
28. Surface workings of mole and pocket gopher 697
29. Yosemite Pocket Gopher in action 699
30. Winter earth cores made by pocket gophers 701
31. Sierra Mountain Beaver and its burrow 702
32. Southern Sierra Marmot 703
33. Long-eared Chipmunk and California Gray Squirrel 704
34. California Gray Squirrel 705
35. Cones of white fir exhumed from caches made by Sierra Chickaree; twig tips of
lodgepole pine cut by Sierra Chickaree 707
36. Granite talus at head of Lyell Canon, home of Yosemite Cony; kitchen middens on
log where Sierra Chickaree had been dissecting red fir cones 709
37. Work of Yellow-haired Porcupine; work of Golden Beaver 711
38. Yosemite Cony and its lookout station 712
39. Mountain Coyote; Mule Deer 713
40. Records in the road 715
41. Cahfornia Gulls on Paoha Island, Mono Lake 717
42. Long-eared Owls 718
43. Band-tailod Pigeons; Nuttall Poorwill; Groat Gray Owl 719
44. Principal diurnal birds of prey in the Yosemite region 720
45. Nests and eggs of Swainson Hawk and Texas Night hawk 721
46. Hummingbirds, Swallows, and White-throated Swift 723
47. Nests of Cliff Swallow and California Linnet 724
48. Marii)osa Fox Sparrow, Green-tailed Towhee, and Sacramento Spurred Towhee.. 725
49. Ne.sts of (Jreon-tailed Towhee and Northeastern Lincoln Sparrow 726
50. Vireos of the Yosemite region 727
[xvi]
PLATE PAGE
51. Nests of California Least Vireo and Tolmie Warbler 728
52. American Dipper 729
53. Western Mockingbird and California Shrike; Dotted Canon Wren and San
Joaquin Bewick Wren 731
54. Western House Wren and nest sites 733
55. Nests of Western Robin and Townsend Solitaire 734
56. Black-billed Magpie and Mountain Bluebird 735
57. Mountain Lizard, Western Fence Lizard and California Whip-tailed Lizard 736
58. Western Skink and alligator lizards 737
59. Valley Gopher Snake and Pacific Rattlesnake 739
60. Some amphibians of the Yosemite region 741
Maps, Colored (at end of half-tone plates)
61. Profile of Yosemite section showing relation of life-zones to altitude and slope
62. Map showing life-zones of Yosemite section
Figures in Text
FIGURE page
1. Zonal restriction of certain mammals 5
2. Zonal restriction of certain breeding birds 7
3. Sample census sheet 23
4. Snout of Yosemite Mole 43
5. Fore foot of Yosemite Mole and of Sierra Nevada Pocket Gopher 44
6. Zonal distribution of shrews 48
7. Pacific Pallid Bat 61
8. Mexican Free-tailed Bat 62
9. Sierra Least Weasel, Mountain Weasel and Pacific Mink 87
10. Heads of white-footed mice 105
11. Zonal distribution of white-footed mice 107
12. Tails of Alexandrine Roof Rat, and of Streator and Gray Bushy-tailed wood rats 116
13. Streator Wood Rat 117
14. Nesting quarters of Streator Wood Rat in log 119
15. Gray Bushy-tailed Wood Rat 121
16. Tails of Yosemite Meadow Mouse and Sierra Cantankerous Meadow Mouse 123
17. Burrow-system of Mariposa Meadow Mouse 128
18. Enlarged section through part of preceding 129
19. Zonal distribution of meadow mice 130
20. Sierra Cantankerous and Yosemite meadow mice and Mountain Lemming Mouse 131
21. Willow association at head of Lyell Canon 132
22. Method of work of mole 136
23. Method of work of pocket gopher 137
24. Zonal distribution of pocket gophers 139
25. Cartoon suggesting relation of pocket gopher work in high mountains to accumu-
lation of fertile sediments in lowlands 143
26. Quill of Yellow-haired Porcupine 152
27. Zonal distribution of squirrels and marmot 163
28. Zonal distribution of chipmunks 178
29. Sierra Chickaree 205
30. Sugar pine cones as worked upon by Sierra Chickaree 206
31. Kitchen middens: remains of cones of Jeffrey pine 207
32. Sierra Flying Squii-rel 212
33. Head of California Jack Rabbit 223
[xvii]
FIGURE PAGE
34. Head of Sierra White-tailed Jack Rabbit 225
35. Heads of Mariposa Brush Rabbit and Sacramento Cottontail Rabbit 229
36. Skulls and horns of Sierra Nevada Mountain Sheep and Domestic Sheep 245
37. Harlequin Ducks 255
38. Debris from beneath Cooper Hawk's nest 285
39. Owls of the Yosemite region 299
40. Debris from beneath Long-eared Owl's nest 303
41. Work of Willow Woodpecker on apple tree 319
42. Feet of Northern White-headed Woodpecker and Arctic Three-toed Woodpecker 326
43. Diagram of workings of Sierra Red-breasted Sapsucker 328
44. Fresh work of Williamson Sapsucker 332
45. Scars on trunk of lodgepole pine, result of work of Williamson Sapsucker 333
46. Head of Northern Pileated Woodpecker 335
47. Head and tongue of California Woodpecker 339
48. Drillings of California Woodpecker and nest site of Lewis Woodpecker 340
49. Head of Clark Nutcracker 395
50. Tails of California Purple Finch and California Linnet 421
51. Bill of Sierra Crossbill and cone and seeds of lodgepole pine 430
52. Bills of Cassin Purple Finch, California Evening Grosbeak, and Sierra Nevada
Rosy Finch 431
53. Tails of Willow, Green-backed, and Lawrence goldfinches, and Pine Siskin 436
54. Tails of Western Lark Sparrow and Western Vesper Sparrow 444
55. Young of Mariposa Fox Sparrow and Pacific Black-headed Grosbeak 489
56. Forage niches of warblers in Yosemite Valley 517
57. Tails of Alaska Myrtle Warbler and Audubon Warbler 527
58. Tails of Sierra Creeper and Red-breasted Nuthatch 562
59. Heads of Sierra Hermit Thrush and Cassin Purple Finch 604
60. Young Western Robin 607
61. Zonal distribution of certain reptiles and amphibians 627
62. Western Yellow-bellied Racer and Giant Garter Snake 637
63. Boyle King Snake and California Striped Racer 641
64. Rattle of Pacific Rattlesnake 647
65. Poi.son apparatus of Pacific Rattlesnake 649
INTRODUCTION
The Area Considered
The region studied is designated in this report as the ' Yosemite region, ' or, more precisely, as the ' Yosemite section. ' It involves, as shown on the accompanying map (pi. 62), a narrow rectangular area, 89l^ miles in length by 17 1/3 miles in width. It reaches from the eastern margin of the San Joaquin Valley eastward across the mountains to include the western margin of the Great Basin, around Mono Lake, and thus constitutes a typical cross-section of the central Sierra Nevada. The altitudes range from 250 feet, at Snelling, to slightly over 13,000 feet, on Mount Lyell. The total 'map' area is 1547 square miles, Yosemite Valley is included in its entirety ; the Valley ends of the Wawona and Big Oak Flat roads are within the ' section, ' as are the greater parts of the Coulterville and Tioga roads. But neither the Mariposa Grove of Big Trees nor Hetch Hetehy Valley is included.
Within the limits of this 'section,' the members of our field party traveled over most of the regular trails (routes are shown on the map) ; in addition they sought out high pointSffrom which practically every square mile of territory could be seen and mapped as to life zone. All together, 40 collecting stations were occupied by different members of our party. The number of persons working at any one station at one time varied from one to five. Certain camps such as those in Yosemite Valley, at Porcupine Flat, on Tuolumne Meadows, and at the Farrington ranch were 'base camps, ' from which short trips were taken in different directions. At all the places marked on the map as collecting stations, trapping for mammals was done on one or more nights.
Statistics of Field Work
The first regular field work of the Yosemite Survey was a reconnaissance trip by the senior author in the autumn of 1914. (Both authors were already familiar with the lay of the land from previous visits to Yosemite Valley and its environs.) Formal field work was instituted on Novem- ber 19, 1914, and continued until January 9, 1915; it was commenced again on May 15, 1915, and continued until July 31 ; it was again taken up on August 16 and carried on until November 23 (1915). In 1916 continuous work was carried on in the neighborhood of Mono Lake from
[1]
2 ANIMAL LIFE IX THE TOSEMITE
April 26 until July 6, That same year, two brief trips were made into Yosemite Valley, at the end of February and at the end of April. In IDli) work in the western part of the region was carried on from May 5 to 27 ; and in 1920 work was in progress there from June 20 until August 11.
Nine hundred and fifty-seven 'man-days' (one man in the field one day) were put in. The field notes written occupy 2001 pages, and the specimens secured bj' our regular field men number 4354. The photographs obtained number 700. In addition, as indicated elsewhere, much valuable information and many important specimens were secured from residents in the Yosemite region.
All the materials upon which this report is based, including specimens, maps, notebooks, and photographs, are now contained in the Museum of Vertebrate Zoology of the University of California and are the property of the State of California.
Field Personnel
Eight different persons participated at one time or another in the field work of the Yosemite Survey; 248 days were put in by Joseph Grinnell, 170 days by Tracy I. Storer, 111 days by AValter P. Taylor, 110 days by Joseph Dixon, 103 days by Charles L. Camp, 92 days by Gordon F. Ferris, 91 days by Charles D. Holliger, and 32 days by Donald D. McLean. It should be understood that whatever degree of accuracy and fullness the present report may possess rests upon the diligence, as field collectors and observers, of each and every one of these persons.
FiEi>D Methods
The general plan of work was much the same at all the collecting stations. It was of course essential, in the interests of truth and scientific accuracy, that many specimens be obtained in order that correct identi- fication of the species might be insured. Hence, each member of the party kept out a line of mouse and rat traps for the capture of the various species of small mammals. These were set in 'likely' places: along stream banks for shrews ; in runways of meadow mice ; about brush heaps or downed logs for Avhite-footed mice, and so on. Special traps were set for moles, for pocket gophers, and for carnivoro\is species. These traps were baited the last thing each evening and were visited early the next morning so as to collect the animals caught before they might be harmed by sunshine or by insects. Where chipmunks abounded, or ground dwelling birds were numer- ous, traps were often visited during the day to recover such animals as were caught; or else the traps Avere pur])osely spning in the morning and reset again in the evening in order 1o avoid capturing nianunals or birds not needed i'or specimens. IJirds were ol)!. 'lined, when necessary, by s]u)oling
INTRODUCTION 3
selected individuals. Many reptiles were captured* by hand, although some of the swifter ones could be obtained only by shooting.
But the taking of specimens was only one of several lines of activity. The morning of each day was usually spent away from camp observing and making notes upon the various species to be seen — their local distri- bution, forage habits, nesting behavior, and all the other observable features connected with their life histories. Each member of the party carried a notebook (journal) in which the observations of each day were recorded. Notes on the behavior of individual animals were written down usually while observation was in progress, to insure the entry of details with accuracy. When nests, burrows, or other 'workings' were examined, the measurements and diagrams were entered directly in the journal. Censuses were gathered as they were taken, the individuals pencil-checked one by one according to the method described fully elsewhere (p. 22). Photographs were taken of 'associations,' workings, tracks, and nests, and these mater- ially supplemented the written data.
Limitation of Time
It became necessary, as in all such undertakings as this, arbitrarily to fix upon a date beyond which no further matter would be incorporated into this report. This date was set as December 31, 1920. Even though important new facts have been reported from the Yosemite region by competent observers since that date, we have forborne inclusion thereof. Inevitably, such additions will continue to be made so long as people with an interest in natural history visit the Yosemite region. The natural history resources will never become exhausted ; and that is one fascinating feature of this field of inquiry. Our efforts, then, have been to assemble all the available information concerning the vertebrate animals of the Yosemite region up to and including December, 1920.
ANIMAL LIFE IN THE YOSEMITE
DISTRIBUTION OF ANIMAL LIFE IN THE YOSEMITE SECTION
Probably the primary stimulus which leads people to visit our national parks is the change that is experienced from familiar surrounding to those which are emphatically different. This change involves 'air' (that is, climate), and 'scene' (topography and vegetation). An entirely new set of conditions is encountered, and the new reactions set up mean recreation in the physiological sense — the exercise of faculties, both mental and physical, in kind or degree, that are more or less dormant during the ordinary routine of the year's program. Quick transportation between the lowlands of the San Joaquin Valley and the upper altitudes of the Sierras carries the traveler in either direction from one set of surroundings into a totally different one where he is thrilled because of the great changes which he encounters.
Let us now discuss, then, these differences in environment and their correlation with the continuous or discontinuous occurrence of vertebrate animals in the region. The section of the Sierra Nevada selected for faunal study is of such extent transversally to the Sierran axis that it takes in almost as great extremes of conditions as are to be encountered anywhere in California. Analysis of the changes to be observed as a person traverses the section from the west ^^^ll soon show that he has witnessed not one single change, evenly and progressively from one set of conditions to just one other set, but that, having reached the highest altitudes, he has witnessed several steps. There has not been a uniform and continual gradient but he has passed through several belts, parallel roughly to the axis of the Sierra Nevada, each characterized by a considerable degree of uniformity as regards the plant and animal life.
A total of 231 kinds of birds are now (December 31, 1920) authentically known from the Yosemite section ; there are 97 kinds of mammals, 22 kinds of snakes and lizards, and 12 kinds of frogs, toads, and salamanders. This makes a grand total, for the vertebrate fauna outside of fishes, of 362 forms. This seeming richness in number of kinds, be it emphasized, is apparent only when one takes into account the full extent of the Yosemite section. As a matter of fact, but a small proportion of the total number of species occur together at any one level. And here is the remarkable thing: They are more or less assorted and delimited in occurrence so that tlioy helji to constitute the belts, or 'life zones,' just referred to.
DISTRIBUTION OF THE ANIMALS
Tule Meadow Mouse Merced Kangaroo Rat
Fresno Pocket Gopher Golden Beaver
San Joaquin Pocket Mouse Sacramento Cottontail Rabbit
Cascade Red Fox Yellow-haired Porcupine Allen Chipmunk
Sierra Wolverine Sierra Least Weasel Mountain Lemming Mouse Southern Sierra Marmot Belding Ground Squirrel Alpine Chipmunk Yosemite Cony
Alpine Chipmunk ' Yosemite Cony
■ Mono Chipmunk
Mono Mole
Short-tailed Grasshopper Mouse Great Basin Pocket Mouse , Pale-faced Kangaroo Rat ?s
Mono Kangaroo Mouse Desert Jack Rabbit Sagebrush Chipmunk Washington Cottontail Rabbit
6 ANIMAL LIFE IN TEE YOSEMITE
We may express the facts in another way. The large number of kinds of animals present in the entire Yosemite section is due to the great range of physical conditions (temperature, moisture, soil, light, and perhaps others) with the accompanying diversity of vegetational features. Man is able to traverse the whole gamut of these conditions, even with benefit to himself by reason of the stimulus change produces, adjusting his mode of dress and behavior to them and carrying his food with him. But animals and plants are more or less directly in contact with the conditions around them ; they are, as a rule, far less adaptable ; and they are vitally affected by differences in temperature, in moisture, in food supply, and so on. The interesting thin^ is that in many species the degree of sensitiveness is so great that they can maintain existence only \vithin a relatively narrow range of the critical conditions.
Such underlying reasons as those just suggested help to explain what impresses the traveler in ascending the west slope of the Sierras, namely, the correlation, roughly, with respect both to animals and plants, of zonation with altitude and, therefore, temperature. And it is because of this inter-correlation that the student is led to the conclusion that it is the factor of temperature which has most to do with the causation of life zones.
Reference to our map and cross-section diagram (pis. 61, 62) will show the application, to the Yosemite section, of the system of recognizing these belts of animal and plant life as some naturalists have worked them out and named them. Each life zone is a belt of relatively uniform constitution with respect to species. At the same time, we must emphasize that there is rarely an abrupt line of demarcation between any two adjoining zones. There is, as a rule, along the meeting ground more or less mixing or over- lapping of the specific elements. Tliis is especially true where the slope is very gentle, broad, and all facing in one direction. The steeper the slope, or the more abrupt the change of exposure (say from west to north), the sharper will be the boundary between the two adjacent zones.
To enter here into a further discussion of the life-zone concept is not necessary. We will simply refer the inquiring reader to some of the literature relating to the subject^ and confine the present treatise to the
iC. Hart Merriam, Life Zones and Crop Zones of the United States (U. S. Dept. Agric, Div. Biol. Surv., Bull. no. 10, 1898), 79 pp., 1 colored map. C. Hart Morriam, Eesults of a Biological Survey of Mount Shasta, California (U. S. Dopt. Agric, Div. Biol. Surv., N. Am. Fauna, no. 16, 1899), 179 pp., 5 pis., 46 figs, in text. H. M. Hall, A Botanical Survey of San Jacinto Mountain (TTniv. Calif. Puhl. Bot., vol. 1, 1902), l)p. 1-140, pis. 1-14. J. Grinnell, An Account of the Mammals and Birds of the Lower Colorado Valley, with Especial Reference to the Distributional Probleius Presented (Univ. Calif. Publ. Zool., vol. 12, 1914), pp. .'51-294, pis. 3-13, 9 figs, in text. J. Grinnell, A Distributional List of the Birds of California (T'ac. Coast Avifauna, no. 11, 1915), 217 pp., 3 maps. H. M. Hall and J. Grinnell, T^ife Zone Indicators in California (Proc. Calif. Acad. Sci., ser. 4, vol. 9, 1919), pp. 37-67.
DISTBIBUTION OF THE ANIMALS
Sierra Grouse Western Goshawk Williamson Sapsucker Hammond Flycatcher Cassin Purple Finch Mariposa Fox Sparrow Townsend Solitaire
Arctic Three-toed Woodpecker . California Pine Grosbeak Hudsonian White-crowned Sparrow
Sierra Nevada Rosy Finch
Hudsonian White-crowned Sparrow
8 ANIMAL LIFE IX THE TOSEMITE
particular state of affairs found in the Yosemite region. Since all animal life is more or less directly dependent upon plant life for its existence, the zoologist who seeks to explain the distribution of animals must concern himself attentively also -with the botany of the region he is studying. A very useful essay on the distribution of plant life on the upper western slope of the Yosemite section is contained in Professor and Mrs. Hall's Yosemite Flora-; and further valuable data on the distribution of plants in the Sierras will be found in a report by Dr. Smiley.^
All of the six life zones in the Yosemite region are represented in full measure on the western slope of the section. There the distance involved in the slope is so great, over seventy miles, that there is plenty of room for the development of a separate representation of species, both plant and animal, in each zone. But on the eastern slope the situation is some- what different ; and we find the zonation there obscure. Indeed, in our field work below the Hudsonian Zone we met with much trouble in diagnosing many of the localities; for instance, whether to call the upper meadows on the Farrington ranch (pi. 19a.), Canadian or Transition; the south face of Williams Butte (pi. 196), Transition or Upper Sonoran.
On the basis of the facts obtained within the eastern boundary of our Yosemite section alone, the situation would be exceedingly difficult, even impossible, of explanation. But when we take into account the ea.st-Sierran region generally, especially toward the southern end of the Sierran ridge in the vicinity of Walker and Tehachapi passes, it becomes fairly easy to see why conditions are as we find them between Mono Lake and Mono and Tioga passes.
Base-level in the Mono Basin is high, averaging 7000 feet in altitude. Furthermore, the distance between Mono Lake and the high Sierran crest, which is 10,000 to 13,000 feet in altitude, is short. In other words, this slope is abrupt ; in fact, close to the divide, a declivity. The life zones, in so far as characteristic representatives of them are to be found, are crowded together — telescoped, as it were. There is a well established law that a sequestered faunal area can be too small to support a permanent, distinctive fauna of its own, even though conditions be otherwise wholly propitious. The Sierra Nevada, which by area is of mainly western slope, supports a large mass of 'boreal' plant and animal life; the Great Basin area to the east is the metropolis of a highly developed 'austral' assemblage of species. These two major areas adjoin one another at the steep eastern declivity of the Sierras. On the long western slope where austral adjoins
2H. M. Hall and C. C. Hall, A Yosemite Flora (Paul Elder, San Francisco, 1912), pp. viii + 282, 170 text figs., 11 pis.
3 F. J. Smiley, A Rejjort upon the Boreal Flora of the Sierra Nevada of California (Univ. Calif. Publ. Bot., vol. 9, 1921), pp. 1-423, pis. 1-7.
DISTBIBUTION OF THE ANIMALS 9
boreal there is not only a well-marked belt of overlapping (comprising the Transition Zone) but in this belt there are numerous species closely restricted to it. On the eastern slope, however, Canadian and Upper Sonoran are jammed so closely together by reason of the steepness that the belt of intermingling of elements is very narrow or at best indistinct ; there is scarcely if any room for the existence of restrictedly Transition Zone species.
Although presenting a strongly Great Basin aspect, the Mono basin, doubtless because of its high altitude, does not show a pure representation of austral life. It does contain a number of elements (that is, species) which from a study of their entire ranges we know to belong predominantly to the upper division of the austral, namely Upper Sonoran. But there are also present about as many, or as dominant, boreal elements.
Frankly, we found difficult}^ in assigning some parts of the Mono portion of the Yosemite section to one life zone rather than to another. This was particularly true of the south, sun-facing slope of Williams Butte (pi. 19&), which is clothed with piiion. This tree to the southward along the Sierras forms a belt which through Walker Pass is continuous with the digger pine belt of the west slope of the Sierras ; and as a rule we can safely diagnose this belt by reason of this one plant indicator as Upper Sonoran. But on Williams Butte the pinons are mixed with western junipers, Jeffrey pines, mountain mahogany, and certain shrubby plants which are accepted as diagnostic of Transition, Canadian, or even Hudsonian. We found in this anomalous assemblage of plants such 'good' Upper Sonoran birds as bush-tits and Woodhouse jays in close association with mountain chickadees and Clark nutcrackers. This was after the breeding season ; and, of course, there was a chance that in the case of the last-named species, at least, the individuals observed had moved down from the higher altitudes but a very few miles to the westward. In the case of small mammals, which are incapable of quickly traversing considerable stretches of territory, we found, on Williams Butte, True white-footed mice, which are typically Upper Sonoran, in the same trap-line with Mono chipmunks, which find their metropolis in the Canadian life zone.
Another tract in the Mono country which was for similar reasons perplexing occupies the lower slope down toward the lake shore from Mono Mills. There, pale-faced kangaroo rats, Stephens soft-haired ground squirrels, and desert jack rabbits were found, species which belong to groups whose habitats lie chiefly within the Upper Sonoran Zone, but here were found in company with animals and plants of more northern, Transition or even Canadian, predilections. The sage-hen, to cite one of these latter, is a ' good ' Transition bird.
10 ANIMAL LIFE IX THE 10 SEMITE
111 the nature of the case, as regards these exceptional localities, we trust that the reader will understand why it is impossible for us to make, positive statements witli regard to their zonal complexion. Two persons, with some difference in perspective — that is, witli a different understanding of the 'importance' of indicators — would very probably weight tlieir find- ings differently. Our conclusion, as shown on our map and in our life-zone table, namely, to call the western part of the Mono Lake basin, that part, included within the Yosemite 'section,' Transition, is therefore presented tentatively. The margin of determination is so small, with regard especially to Williams Butte and the tract immediately south of Mono Lake, that someone else, working the territory more intensively and listing the critical species statistically (by individual composition, w'hich we did not), might find adequate grounds for mapping it as Upper Sonoran.
Returning to the Sierran divide: The Hudsonian Zone is found to be well characterized on the east slope down to an average of about the 9500- foot contour. This zone simply mantles the Sierras, save for the Arctic- Alpine 'islands' which rise above timber line. Below the Hudsonian, good Canadian is represented, with marked resemblance florally to that on the western slope, in the lower part of Bloody Caiion. Moisture conditions are there more exactly as they are on the west flank of the Sierras. Else- where, Canadian is rather different in aspect from what it looks like on the western slope, because of the prevailing aridity. Jeffrey pines and mountain mahogany predominate in the place of red firs and aspens. The steepest declivities, close to the Sierran divide, involve a lowering of altitude to about the 8000-foot contour; thence eaiit to Mono Lake the slopes involved in the long, lateral moraines are gentle, and the blending of Canadian through Transition with 'austral' takes place gradually over several miles of territory. Here is where most trouble wa-s experienced in fixing upon a boundary between Canadian and Transition — and for the same reasons as given above with respect to the Transition-Upper-Sonoran boundary. Good Canadian extends east along the cold streams, where it is marked conspicuously by thickets of aspen, well down toward the shores of Mono Lake — to as low as 7000 feet ; Transition extends west up toward the foot of the east Sierran face, especially along the south-facing slopes of glacial ridges, to 9000 feet. Thus at Walker Lake one finds the interest- ing situation of the Canadian Zone occupying the cool, shaded bed of the glacial groove, with Transition on tiie south, sun-facing Avail above it : the usual zonal relationship is reversed. Pacts such as this strengthen our belief that the prime i)hysical factor accounting for zonation is not altitude, or moisture, or soil, per se, but temperature.
DISTRIBUTION OF TEE ANIMALS 11
As is clearly set forth in some of the literature we here cite for perusal by the inquiring reader, the limitation of species on the basis of the life- zone concept is not the only sort of segregation which occurs. Indeed, locally, as in Yosemite Valley proper, often a far more conspicuous manner of delimitation is manifest, the delimitation which takes place on the basis of 'associations.' These minor units involve each a certain type of environment within one zone ; furthermore, closely similar or even identical associations may recur, or be continuous, in two or more adjacent zones. Not rarely, associational restriction seems to be transcendent over zonal restriction, as in the case of the badger, western chipping sparrow, and rock wren. Appropriate discussion of these cases will be found in the chapters (pp. 92, 452, 550) treating of these species.
Some of the more important associations of animal with plant or sub- stratum conditions that it has proved useful to recognize in the Yosemite section are as follows, classified by zones. The names chosen are those of some predominating feature, usually of the vegetation. (Consult plates 13 to 19, 36o, and figure 21.)
ASSOCIATIONS WITHIN THE LOWEE SONOEAN ZONE
Open-water (two types, Eiver and Eose-thicket
Slough) Valley-oak
Eiparian (Willow-cottonwood) Hog-wallow prairie
Marsh Eock outcrop Meadow
ASSOCIATIONS WITHIN THE UPPEE SONOEAN ZONE
Stream Digger-pine
Eiparian (Willow) Blue-oak
Meadow Dry grassland
Live-oak Eocky-slope Chaparral (two types, Adenostoma and Ceanothus cuneatus)
ASSOCIATIONS WITHIN THE TEANSITION ZONE
Swift-stream Black-oak
Eiparian (two types, Willow-cotton- Golden-oak
wood and Alder) Yellow-pine
Meadow Silver-fir
Dry grassland Boulder-talus
Chaparral (two tj^es, Sticky-man- Cliff
zanita and Buckthorn)
ASSOCIATIONS ON THE AEID EAST SIDE OF THE SIEEEA, IN THE GEEAT BASIN FAUNAE DIVISION OF THE TEANSITION ZONE
Alkali-lake Sagebrush
Eiparian (Willow) Pinon-juniper
Eose-thicket Cercocarpus Shepherdia
12 ANIMAL LIFE IN THE YO SEMITE
ASSOCIATIONS WITHIN THE CANADIAN ZONE
Swift-stream Bed-fir
Biparian (two types, Willow and Lodgepole-pine
Comus pubescens) Jeffrey-pine
Aspen Granite outcrop
Meadow Cliff Chaparral (three types, Bed-cherry,
Arctostaphylos patula, and
Huckleberry-oak)
ASSOCIATIONS WITHIN THE HUDSONIAN ZONE
Lake Lodgepole-pine
Shore Hemlock
Swift-stream Whitebark-pine
Biparian (Willow) Talus (or Bock -slide)
Meadow Cliff Heather
ASSOCIATIONS WITHIN THE AECTIC-ALPINE ZONE
Swift-stream Dry grassland
Willow-thicket Talus (Bock-slide)
Meadow CUff
Within each general association there is often plainly to be seen still further restriction in the habitat preferences of species. For example, in the major association, "coniferous forest," in its minor division (within the Canadian Zone) known as the red-fir association, we find several species of birds and of mammals, each adhering closely to a yet smaller division of the general environment. The Sierra Creeper keeps to the larger tree trunks, the Short-tailed Mountain Chickadee to the smaller twiggery, the Western Golden-crowned Kinglet to the terminal leafage, and the Ham- mond Flycatcher to the most prominent twig-ends and the air-spaces between branches and between trees. The Tahoe Chipmunk is largely arboreal, the Allen Chipmunk terrestrial.
In final analysis, no two species well established in a region occupy precisely the same ecologic space; each has its own peculiar places for foraging, and for securing safety for itself and for its eggs or young. These ultimate units of occurrence are called "ecologic niches." If two species of the same ecologic predilections are thrown into the same environ- ment, one or the other will quickly disappear through the drastic process we call competitive replacement. Thus it comes to pass that the amplitude of the general environment — the number and extent of distinct ecologic niches it compasses — determines the richness of the fauna, both as regards number of species, and the number of the individuals to the unit of area representing each species. This principle may be abundantly verified by any student who will carry on active field observations a season or two over even a small part of the Yosemite section.
14 ANIMAL LIFE IN THE YO SEMITE
Table of Occurrence, According to Life Zone, of the Mammals,
Breeding Birds, Reptiles, and Amphibians of
the yosemite section
Note. — It is intended, in the using of this table, that comparison be made with the life-zone map and profile, plates 61, 62. Width of bar indicates relative abundance of the species concerned; in other words, the widest place in the bar indicates the place, zonally, where the popula- tion is believed to be densest. In case there is some reason to suppose that a species ranges beyond what is shown by the actual facts at hand, such extension is indicated by a broken line. Some of the species which are listed in the present work are omitted from the table because they are non-native, extinct, or of unknown or doubtful status. Water birds are omitted entirely, as are also non-breeding land birds.
It must be distinctly understood that this table of zonal distribution is based on our findings in the Yosemite region only ; it must not be inter- preted as setting forth the distributional situation in the Sierra Nevada generally, or in the State at large, though this may approximately be true in the great majority of cases. The zonal diagnoses of species apply primarily to the long, western slope of the Sierra Nevada; many of the species occur only on that side. Exclusively east-side species are so indi- cated by foot-note reference ; and where these latter are known to extend into the Transition Zone from the Upper Sonoran Zone (hence beyond the limits of our section) this fact is indicated by cutting off the bar squarely at the vertical line of demarcation between these two zones.
DISTBIBUTION OF THE ANIMALS
15
^ -5
Yosemite Mole, Scapanus I. sericalus
San Joaquin Mole, Scapanus I. campi
*Mono Mole, Scapanus I. monoensis
Dusky Shrew, Sorex o. obscurus
Adorned Shrew, Sorex ornatus
Yosemite Shrew, Sorex in. mariposae
•Sierra Nevada Shrew, Sorex v. amoenus
Navigator Shrew, Neosorex p. naiigator
Little California Bat, Myotis c. californicus
High Sierra Bat, Myolis I. altipetens
Long-legged Bat, Myolis I. longicrus
Fringed Bat, Myotis thysanodes
Merriam Bat, Pipistrellus h. rr.erriami
Large Brown Bat, Eptesicus fuscus
Hoary Bat, Nycteris cinerea
Pacific Pallid Bat, Antrozous pacificus
Mexican Free-tailed Bat, Nyctinomus mexicanus
American Black Bear, Ursus americanus
Mountain Coyote, Cam's I. testes
Cascade Red Fox, Vulpes cascadensis
San Joaquin Kit Fox, Vulpes m. rr.ulica
California Gray Fox, Urocyon c. californicus
California Ring-tailed Cat, Bassariscus a. raptor
California Coon, Procyon I. psora
Sierra Pine Marten, Martes c. sierrae
Pacific Fisher, Martes p. pacifica
Sierra Nevada Wolverine, Gulo I. luleus
Mountain Weasel, Mustela arizonensis
Sierra Least Weasel, Mustela muricus
Pacific Mink, Mustela v. energumenos
California Spotted Skunk, Spilogale p. phenax
Striped Skunk, Mephitis occidenialis
California Badger, Taxidea I. neglecla
Northwestern Mountain Lion, Felis o. oregonensis
California Wildcat, Lynx e. californicus
Gambel White-footed Mouse, Perotnyscus m. gambeli
*Sonora White-footed Mouse, Peromyscus m. sonoriensis
Boyle White-footed Mouse, Peromyscus b. boylii
Gilbert White-footed Mouse, Peromyscus t. gilberti
* On east side of Sierras only.
16
ANIMAL LIFE IX THE YO SEMITE
3 (2
^ I
a. S
True White-footed Mouse, Peromyscus I. truei
Parasitic White-footed Mouse, Peromyacus c. catifomiau
•Short -tailed Grasshopper Mouse, Onychomys I. brevicaudua
Long-tailed Harvest Mouse, ReithrodorUomys m. longicauda
Strcator Wood Rat, \eolomaf sireatori
Gray Bushy-tailed Wood Rat, Neotoma c. cinerea
Yosemite Meadow Mouse, Microlus m. yosemite
Tule Meadow Mouse, MtcrotU3 c. acstuarinua
Mariposa Meadow Mouse, Microtus c. mdriposae
Sierra Cantankerous Meadow Mouse, Microtus m. sierrae
"Short-tailed Meadow Mouse, Lagurus curtatus
Mountain Lemming Mouse, Phenacomys orophilus
Fresno Pocket Gopher, Thomomys b. pascalis
Digger Pine Pocket Gopher, Thomomys b. meua
Yosemite Pocket Gopher, Thomomys a. au-ahnee
Sierra Nevada Pocket Gopher, Thomomys m. monlicola
•Fisher Pocket Gopher, Thomomys q fisheri
Cahfornia Pocket Mouse, Perognuthus c californicus
San Joaquin Pocket Mouse, PerognaOnts i inornalus
'Great Basin Pocket Mouse, Perognuthus p oliiaceus
Heermann Kangaroo Rat, Dipodomys h. heemtanni
Merced Kangaroo Rat, Dipodomys h dizoni
•Pale-faced Kangaroo Rat, Dipodomys teucogenys
•Mono Kangaroo Mouse, Microdipodops polionotus
Allen Jumping Mouse, Zapus p attcni
Yellow-haired Porcupine, Erethizon e. epixanthum
Sierra Mountain Beaver, Aplodontia r califomica
Southern Sierra Marmot, Marmota f sierrae
California Ground Squirrel, Citcltus b becchcyt
Bclding Ground Squirrel, Cittllus beldingi
•Stephens Soft-haired Ground Squirrel, Citellus m. stephensi
Sierra Nevada Golden-mantled Ground Squirrel Callospermuphilus c. chrysodeirus
Tahoe Chipmunk, Eulamias s frater
Allen Chipmunk, Eulamias senez
Mariposa Chipmunk, Eulamias m. mariposae
Long-eared Chipmunk, Eulamias quadrimaculalus
Alpine Chipmunk, Eulamias alpittua
•Mono Chipmunk, Eulamias a. monoensia
•Sage brush Chipmunk, Eulamias jrictua
• On east side of Sierras only.
DISTBIBUTION OF THE ANIMALS
17
S 2
California Gray Squirrel, Sciurus g. griseus
Sierra Chickaree, Sciurus d. albolimbatus
Sierra Flying Squirrel, Glaucomys s. lascimis
Golden Beaver, Castor c. subauratus
Yosemite Cony, Ochotona s. muiri
California Jack Rabbit, Lepus c. califomicus
*Desert Jack Rabbit, Lepus c. deserlicola
Sierra White-tailed Jack Rabbit, Lepus I. sierrae
Sacramento Cottontail, Sylirilagus a. aTuiubonii
Washington Cottontail, Syhnlagus n. nuUaUii
Mariposa Brush Rabbit, Sylvilagus b. mariposae
Mule Deer, Odocoileus h. hemionus
Mountain Quail, Oreortyx p. plumijera
Valley Quail, Lophortyx c. vallicola
Sierra Grouse, Dendragapus o. sierrae
*Sage-hen, Centrocercus urophasianus
Band-tailed Pigeon, Columba f. fasciata
Western Mourning Dove, Zenaidura m. marginetla
Turkey \'ulture, Calhartes a. septentrionalis
Sharp-shinned Hawk, Accipiter velox
Cooper Hawk, Accipiter cooperi
Western Goshawk, Astur a. striatulus
Western Red-tailed Hawk, Buteo b. calurus
Red-bellied Hawk, Buteo I. elegans
Swainson Hawk, Bvteo sumnsoni
Golden Eagle, Aquila chrysaetos
American Sparrow Hawk, Fako s. sparverius
Barn Owl, Tyto pratincola
Long-eared Owl, Asia vnlsonianus
California Spotted Owl, Strix o. occidentalis
Great Gray Owl, Scotiaptex n. nebulosa
Saw-whet Owl, Cryptoglaux acadica
Southern California Screech Owl, Otus a. quercinus
Pacific Homed Owl, Bubo v. pacificus
Burrowing Owl, Speotyto c. hypogaea
CaUfomia Pigmy Owl, Glaucidium g. califomicum
Road-runner, Geococcyx califomianus
Western Belted Kingfisher, Ceryle a. caurina
Modoc Woodpecker, Dryobates v. orius
* On east side of Sierras only.
18
ANIMAL LIFE IN THE TOSEMITE
Willow Woodpecker, Dryobalcs p. turati
Nuttall Woodpecker, Dryohata nuttalli
T9?
Northern White-headed Woodpecker, Xenopicui a. albohn'alu
Arctic Three-toed Woodpecker, Picoidea arclicus
Sierra Red-breasted Sapsucker, Sphyrapicus v. daggelli
Williamson Sapsucker, Sphyrapicus t. thyroideus
Northern Pileatod Woodpecker, Phloeolotnus p. abieticola
California Woodpecker, Melanerpesf. bairdi
Red-shafted Flicker, Colaptes c collaris
Dusky Poor-will, Phalaenoptilus n. califomicus
•Nuttall Poor-will, Phalaenoptilm n. nuttalli
Pacific Nighthawk, Chordeiles v. hesperis
Texas Nighthawk, Chordeiles a. teiensis
Northern Blade Swift, Cypseloides n. borealis
White-throated Swift, Aeronauies melanoleucits
Black-chinned Hummingbird, Architochus alexaruiri
Anna Hummingbird, Calypte anna
Calliope Hummingbird, Stellula calliope
Western Kingbird, Tyrannus verticalis
Ash-throated Flycatcher, Myiarchus c. cinerascens
Black Phoebe, Sayornis nigricans
Olive-sided Flycatcher, Nuttallornis borealis
Western Wood Pewec, Myiochanes r richardswti
Wright Flycatcher, Empidonax urighli
Hammond Flycatcher, 'Empidonax haminondi
Traill I'ly catcher, Empidonax t. traiili
Western Flycatcher, Empidonax d. difficili:
•Gray Flycatcher, Empidonax griscus
California Horned Lark, Olocoris a. aclin
•Black-billed Magpie, Pica p. hudsonia
Blue-fronted Jay, Cyanocitta s. frontalis
Interior California Jay, Aphelocoma c. immanis
•Woodhouse Jay, Aphelocoma woodhousei
Clark Nutcracker, Nucifraga columbiana
•Pifion Jay, Cyanocephalus cyanocephalus
Dwarf C'owbird, Molothrus a. obscurut
•Nevada Cowbiid, Molothrus a. arlemisiae
Bi-colored Red- winged Blackbird, Agelaius p. califomicus
•Nevada Red-winged Blackbird, Agelaius p. netxtdentii
• On east side of Sierras only.
DISTRIBUTION OF TEE ANIMALS
19
^ ^
Kern Red-winged Blackbird, Agelaius p. aciculalus
Tri-colored Blackbird, Agelaius tricolor
Western Meadowlark, Stumella neglecta
Bullock Oriole, Icterus bullocki
Brewer Blackbird, Euphagus cyanocepfialus
California Evening Grosbeak, Hesperiphona v. califomica
California Pine Grosbeak, Pinicola e. califomica
California Purple Finch, Carpodacus p. califomicus
Cassin Purple Finch, Carpodacus cassini
California Linnet, Carpodacus m. frontalis
Sierra Nevada Rosy Finch, Leucoslicte t. dawsoni
Willow Goldfinch, AstragalinTis t. salicamans
Green-backed Goldfinch, Astragalinus p. hesperophilus
Lawrence Goldfinch, Astragalinus lawrencei
Pine Siskin, Spinus p. pinus
•Western Vesper Sparrow, Pooecetes g. confinis
'Nevada Savannah Sparrow, Passerculus s. nevadensis
Western Grasshopper Sparrow, Ammodramus s. bimaculalus
Western Lark Sparrow, Chondestes g slrigatus
Hudsonian White-crowned Sparrow, Zonotrichia I. leucophrys
Western Chipping Sparrow, Spizella p arizonae
*Brewer Sparrow, Spizella breweri
Sierra Junco, Junco o. thurberi
Bell Sparrow, Amphispiza belli
*Nevada Sage Sparrow, Amphispiza n. nevadensis
Rufous-crowned Sparrow, Aimophila r. ruficeps
*Modoc Song Sparrow, Melospiza m. jisherella
Northeastern Lincoln Sparrow, Melospiza I. lincolni
Mariposa Fox Sparrow, Passerella i.. mariposae
•Mono Fox Sparrow, Passerella i. morwensis
Sacramento Spurred Towhee, Pipilo m. falcinellus
•Nevada Spurred Towhee, Pipilo m. curtatus
Northern Brown Towhee, Pipilo c. carolae
Green-tailed Towhee, Oberholseria chlorura
Pacific Black-headed Grosbeak, Zamelodia m. capilalis
California Blue Grosbeak, Guiraca c. salicarius
Lazuli Bunting, Passerina amoena
Western Tanager, Piranga ludoviciana
Cliff Swallow, Petrochelidon I. lunifrons
* On east side of Sierras only.
20
ANIMAL LIFE IX THE YOSEMITE
* On caal side of Sierras only
DISTRIBUTION OF THE ANIMALS
21
Western Golden-crowned Kinglet, Regulus s. olivaceus
t °
.3 -s
^ -5
Western Ruby-crowned Kinglet, Regulus c. cineraceus
Western Gnatcatcher, Polioptila c. obscura
Townsend Solitaire, Myadestes Unimsendi
Russet-backed Thrush, Hytocichla u. ustutata
Sierra Hermit Thrush, Hylocichla g. sequoiensis
Western Robin, Planesticus m. propinquus
Western Bluebird, Sialia m. occi'dentalis
Mountain Bluebird, Sialia currucoides
Western Fence Lizard, Sceloporus o. occidentalis
•Pacific Blue-bellied Lizard, Sceloporus o bi-seriatus
Tenaya Blue-bellied Lizard, Sceloporus o. iaylori
Mountain Lizard, Sceloporus g gradosus
California Horned Toad, Phrynosoma b. fronlale
San Diego Alligator Lizard, Gerrhonotus s. uebbii
Sierra Alligator Lizard, Gerrhonotus palmeri
California Whip-tailed Lizard, Ctiemidophorus t. mundus
Western Skiiik, Plesliodon skillonianus
Rubber Snake, Charina bottae
Pacific Garter Snake, Thamnophis s. infemalis
Mountain Garter Snake, Thamnophis o. elegans
Western Ring-necked Snake, Diadophis a. amabilis
Coral King Snake, Lampropellis multicincta
Boyle King Snake, Lampropellis g. boylii
California Striped Racer, Coluber lateralis
Valley Gopher Snake, Pituophis c. heermanni
Pacific Rattlesnake, Crolalus oreganus
Pacific Mud Turtle, Clemmys marmorata
Pacific Coast Newt, N olophthahnus torosus
Mount Lyell Salamander, Eurycea platycephala
Arboreal Salamander, Aneides I. lugubris
Slender Salamander, Batrachoseps attenuatus
•Western Spade-foot Toad, Scaphiopus h. hammondii
California Toad, Bufo b halophilus
Yosemite Toad, Bufo canorus
Pacific Tree-toad, Hyla regilla
California Yellow-legged Frog, Rana b boylii
Sierra Yellow-legged Frog, Rana b sierrae
California Red-legged Frog, Rana a. draytonii
* On east side of Sierras only
22 ANIMAL LIFE IN THE YO SEMITE
CENSUSES OF BIRDS IN THE YOSEMITE SECTION
To convey an adequate idea of the bird life of any given area, enumer- ations of species are not alone sufficient; the numbers of indivkluals of each species must also in some way be indicated. The usual terms ' ' abundant, ' ' "common," "rare," and the like, are unsatisfactory in that their meaning varies both with the person employing them and with the kinds of birds considered. In the latter regard, the Western Chipping Sparrow and the Western Red-tailed Hawk might both be put down as ' ' common, ' ' whereas the sparrow may have been observed in actual numbers ten times those of the hawk.
Counts of individual birds are fairly practicable when made in the breeding season on the basis of some unit of area such as an acre. At that season each adult pair is settled within a particular circumscribed locality, and the male is in song. But as soon as the young are out, and from then on throughout the year until the beginning of the next nesting season, most species of birds are moving about incessantly. Counts of individuals are then very difficult to make and furthermore are likely to be misleading because of their great variation in any small area from hour to hour and from day to day. And so, in our field work in the Yosemite region, we put into effect the following different method.
Instead of using a unit of area, we used a unit of time. Birds were listed, as to species and individuals, per hour of observation. In a general way this record involved area, too. Our censuses were practically all made on foot, and the distance to the right or left at which the observer could see or hear birds did not differ, materially, in different regions. The rate of the observer 's travel did, of course, vary some ; for example, when climbing a steep trail, or going through chaparral, progress was slower than when hiking straightaway along open ridges. Also, in some places, the greater density of the vegetational cover acted to limit the range of sight. But for each of these adverse features of the method there were certain compensations.
For recording a census, a piece of cardboard and a pencil wore carried, the names of the various species of birds jolted down, and their numbers checked, as they came to notice. The presence of no species was assumed ; but probabilities were given consideration in making identifications. In cases where birds were seen or heard, but their identity was not established with certainty, provisional names were entered, each followed by a question
CENSUSES OF BIBDS
23
|
MUSEUM OF VERTEBRATE ZC Date.(A£>;iJ.^S'.y\m(^ |
)OLOGY Nature of route (2 Wcarter.C^&C/lvt |
one, /aun( |
CENSUS SHEET 1, assodaKon$)JiaA!4iii9>i. |
||||
|
Observer ,CiO-<l^. Av S.-foOC^ TimcinfieW.J...-rV«T^-/T^ A;)proiimafe no. mi7cs___V- |
|||||||
|
Species Hour* »> > |
f2^^-2 |
4-0 30 |
f^.^is |
f.M, |
Totals |
||
|
BluA- KovubJcJoM |
/ |
/ |
|||||
|
O tatrtA vUAtto |
5 |
£ |
G |
/3 |
|||
|
dtuiuJ^ IOcxaM^ |
/(? |
3 |
/:3 |
||||
|
^ulpA'CnGUIYUid lOMqjljdt |
(0 |
1 |
7 |
||||
|
rUrwn |
£ |
V |
6 |
||||
|
(J 0/1.6^ |
^ |
7 |
3 |
/V |
|||
|
C^laoiM/i opaMcpO |
/ |
2 |
^ |
iT |
|||
|
lAikvi |
e |
1 |
1 |
^ |
|||
|
Ofii<U/€^4>0 (xy<I4M>/2/ |
^± |
1 |
3± |
||||
|
VflGU/iUJlu/y\ (%JucM.Q.AjiL> |
1 |
1 |
Z |
||||
|
Gleiuia C>ijLaja£lv |
^ |
Z |
1 |
5" |
|||
|
G-o^cte/yi-C/i6wywri( KIm.M' |
^, |
-^ |
1 |
6 |
|||
|
lUedt (Jflt/J^^a /mo |
3 |
Z |
^ |
7 |
|||
|
CoAGvy, VubLo |
3 |
Z |
3 |
S |
|||
|
C^. H |
LdlUo U)cuii^ |
,=? |
1 |
1 |
.5- |
||
|
(^jA ^ |
boA^ |
1 |
/ |
||||
|
(Bidtfe-cl KOvt«y^cc^?uLa |
t |
/ |
|||||
|
(6r.oi^f€/i/ €iU«A^rW;( |
9 |
3 |
|||||
|
(Bfloui- ^QjoMA GAxxJkil. |
1 |
1 |
|||||
|
U^iMcrvo U)frT>7^QaoW; |
1 |
1 |
|||||
|
lRii.-si»va|tri 'PUkw |
1 |
1 |
|||||
|
(BoMcl- i"acfieO( Ptcii2xm |
ICt)+ |
\00+ |
|||||
|
?r(Mi;A>\.aA\ tOAfiyvl |
1? |
1 r |
|||||
|
TOTALS |
(hourly and grand) |
H8 |
3Z |
IZ^f |
ZOS* |
Fig. 3. A sample census sheet.
24 AMMAL LIFE IS THE YOSEMITE
mark. Occasionally the bird could be identified only a-s to its general grouping, as "hawk." Species of very close resemblance were sometimes grouped together in a joint entry; for example, the crowned sparrows (Zonotrichia). The plus sign indicated that more were present than the actual number entered : the birds could not be counted with certainty ; flocking birds, for instance, frequently could not be counted accurately.
At the close of the day or of the period of observation, we were accus- tomed to transfer our censuses from the field sheet (more or less scribi)led. in lead pencil) to our permanent notebooks. If but few species of birds had been seen, these were entered seriatim with numbers of each observed, and comments ; if a goodly census had been secured we entered the results in more formal, tabular style, on special sheets printed for this pur- pose (fig, 3). In either case, record was kept of exact time involved, approximate distance covered, nature of territory traversed, and weather conditions.
Totals were computed, both of species and individuals. Comparisons of these totals for different parts of the Yosemite region and for different seasons have brought forth some interesting conclusions. Outstanding among these generalizations are the following: The greatest bird popu- lation, both summer and winter, is found in the Upper Sonoran Zone. Next come the Lower Sonoran and Canadian zones. The Transition Zone ha-s a fairly large population in summer, but its population drops far down in winter. The Hudsonian has the sparsest summer population, except, of course, for the Alpine-Arctic. The winter population below the snow line consists more largely of seed and berry eaters than of insect feeders ; the summer population everywhere contains a predominating proportion of insect-eating birds.
"We present below a series of censuses, selected from the more than 250 in our notebooks. The censuses given are chosen to illustrate, first, the nature of the avifauna in various representative parts of the Yosemite section, and, second, the marked changes in bird life taking place in Yosemite Valley from season to season through the year.
The series of censuses given for Yosemite Valley is more complete than for any other station in the section. It begins at the height of the nesting season with two censuses on se])arate days in two different parts of the Valley, embracing widely different sorts of habitats (associations) an<l consequently unlike assemblages of birds. The decline of song and general activity at the end of the nesting sea.son is indicated in the census of July 30. That for October 25 shows replacement of the summer visitants by winter invaders. The censuses of December 10 and February 2i) show how completely the Valley is deserted by birds with the advent of the midwinter snows; there are scarcely one-fourth as many birds present
CENSUSES OF BIRDS 25
there in midwinter as in early summer. Return of summer species is already much in evidence in the list made on April 29.
In the census at Mono Lake Post Office on May 31 a 'wave' of migration is indicated in the numbers of species and individuals of warblers seen, which are in excess of what would be present there a month later, in the height of the nesting season. The census on the Big Oak Flat Road in December exhibits the congregation, in a favorable situation, of berry- eating species such as the Townsend Solitaire and Western Bluebird. Had it not been for the berry-laden mistletoe in the golden oaks on the talus slope (pi. 16a) this census in all likelihood would have been no larger than the one taken at the same season on the floor of the Valley.
The census-taker is struck by the variation in his records from hour to hour during the day, irrespective of kind of territory covered and of his own degree of alertness. This fluctuation is due in large part to the fact that there are two daily periods of marked activity on the part of birds, namely, in the early morning, within an hour or so after sunrise, and in the late afternoon, about two hours before sunset. Of these two periods, that in the morning is the most impressive ; in other words the observer, by selecting the earlier hours for his census-walk, will make the highest score and also the most representative one. It is quickly apparent that in comparing the enumerations for different days and for different localities, allowance should be made for this daily double fluctuation in the visibility and audibility of birds.
It is the earnest recommendation of the authors that observers in a position to do so will get into the habit of taking bird censuses. The method here advocated is a practicable one ; we believe it can be adopted to advan- tage by anyone possessed of a fair acquaintance with bird species. A 'collection' of census records will afford basis for much future satisfaction. On the one hand, is the pleasure of recalling to mind pleasant days afield spent among the most attractive things in nature; and on the other hand is the intellectual enjoyment derived from comparing bird populations in kind and size from place to place and season to season, and from endeavoring to account for the fluctuations which are shown, on the basis of all the factors known to control the birds ' existence.
26
ANIMAL LIFE IN THE YOSEMITE
Skelling, altitude 250 feet, Lower Sonoran Zone, riparian association ; January 6, 1915, 9:30 a.m.-12:00 m. ; rain the night previous, the morning somewhat cloudy; dis- tance covered about 3 miles, within a mile east of the town.
Pied-billed Grebe I
California Great Blue Heron 4
Mudhen 1
American Sparrow Hawk 2
Black Phoebe 6
Interior California Jay 8
Brewer Blackbird lOO-f
California Linnet 10+
Willow Goldfinch 6+
Green-backed Goldfinch 4
Intermediate White-crowned Sparrow 10
Golden-crowned Sparrow lO-l-
Total: species 24, individuals 237-f.
Song Sparrows (2 subsp.) 12-f
Northwestern Lincoln Sparrow 2
Sacramento Spurred Towhee 8
Northern Brown Towhee 4
California Shrike 2
Orange-crowned Warbler 2
Tule Yellowthroat 10
Western Mockingbird 6
San Joaquin Bewick Wren 1
Western House Wren 1
California Bush-tit 15-1-
Western Ruby-crowned Kinglet 12
Snelling, 250 feet. Lower Sonoran Zone, riparian association; May 26, 1915, 6:00- 9:00 A.M.; warm, sunny; distance covered about 3 miles, close to Merced River, within a mile east of the town.
California Great Blue Heron 3
Black-crowned Night Heron 1
Killdeer 2
Valley Quail 4
Western Mourning Dove 40-f
Turkey Vulture 1
Red-bellied Hawk 1
American Sparrow Hawk 2-1-
California Woodpecker 2
Lewis Woodpecker 1
Red-shafted Flicker 12-1-
Western Kingbird 10
Ash-throated Flycatcher 6+
Black Phoebe 6
Western Wood Pewee 12 1-
Traill Flycatcher 10-t-
Interior California Jay 4
Western Crow 2
Bicolored Red-winged Blackbird 87-h
Western Meadowlark 12-I-
Bullock Oriole 20
Total: species 41, individuals 427-I-.
Brewer Blackbird 8
California Linnet 50-1-
Willow Goldfinch 40-1-
Green-backed Goldfinch 6
Western Lark Sparrow 1
Western Chipping Sparrow 1
Sacramento Spurred Towhee 10+
Northern Brown Towhee 7
Pacific Black -headed Grosbeak 10
California Blue Grosbeak 6
Lazuli Bunting 10+
Barn Swallow 4
Western Warbling Vireo 1
California Least Vireo 4
California Yellow Warbler Si
Tule Yellowthroat 8+
Long-tailed Chat 6+
Western Mockingbird 1
San Joaquin Bewick Wren 6
Russet-backod Thrush 2
CENSUSES OF BIRDS
27
Pleasant Valley westward toward Forty-nine Gap and return, 600 to 1100 feet, Upper Sonoran Zone, blue-oak, chaparral and grassland associations; February 27, 1916, 7:30-9:30 A.M., and 10:30 a.m.-12:00 m. (actual census time 3 hours 30 minutes); cloudy, with rain 9:30-11:30; distance covered about 6 miles, all on foot, chiefly along roadways.
Valley Quail 1
Turkey Vulture 5
Western Red-tailed Hawk 1
Nuttall Woodpecker 1
California Woodpecker 11
Red-shafted Flicker 4
Black Phoebe 2
California Horned Lark 33
Blue-fronted Jay 1
Interior California Jay 15
Western Meadowlark .' 37
Brewer Blackbird 2
California Linnet 7
English Sparrow 2
Western Lark Sparrow 10
Golden-crowned and Intermediate sparrows 87
Total: species 31, individuals 386.
Sierra Junco 50
Sacramento Spurred Towhee 8
Northern Brown Towhee 15
California Shrike 3
Hutton Vireo 1
Audubon Warbler 2
California Thrasher 1
San Joaquin Bewick Wren 10
Plain Titmouse 9
Pallid Wren-tit 2
California Bush-tit 11
Slender-billed Nuthatch 7
Western Ruby-crowned Kinglet 1
Western Robin 5
Western Bluebird 42
Pleasant Valley westward to high hill near Forty-nine Gap and return, 600 to 1700 feet. Upper Sonoran Zone, blue-oak, chaparral and grassland associations; May 24, 1915, 7:30 a.m.-12:30 p.m.; the day cloudy, considerable rain the night previous; dis- tance covered about 8 miles.
Killdeer 4
Valley Quail 4
Western Mourning Dove 30-1-
Turkey Vulture 20-1-
Cooper Hawk I
Western Red-tailed Hawk I
Nuttall Woodpecker 12-t-
California Woodpecker 10-f-
Lewis Woodpecker 8-f-
Red-shafted Flicker 2
Anna Hummingbird 1
Western Kingbird 6
Ash-throated Flycatcher 25-1-
Olive-sided Flycatcher 1
Western Wood Pewee 20-f
Wright (?) Flycatcher en- Interior California Jay 8-f-
Western Meadowlark 20-t-
Bullock Oriole 25-t-
Brewer Blackbird 20-F
California Linnet 40-1-
Green-backed Goldfinch 10
Western Lark Sparrow 20-i-
Western Chipping Sparrow 8
Northern Brown Towhee 4
Total: species 48, individuals 488-I-.
Pacific Black-headed Grosbeak 6
Lazuli Bunting 6
Western Tanager 10-1-
Cliff Swallow 10
Barn Swallow 4
Northern Violet-green Swallow 20+
Phainopepla 8-h
California Shrike 1
Cassin Vireo 4
California Least Vireo 1
California Yellow Warbler 2
Townsend Warbler 4
Warblers (species?) 10-1-
Long-tailed Chat 3
California Thrasher 1
Rock Wren 2
Dotted Canon Wren 2
San Joaquin Bewick Wren 6-!-
Plain Titmouse 30-1-
California Bush-tit 8-t-
Pallid Wren-tit 6
Western Gnatcatcher 16-1-
Russet-backed Thrush 2
Western Bluebird 20+
28
ANIMAL LIFE IN TEE YO SEMITE
Smith Creek (Dudley), 3000 feet, Transition Zone, riparian, grassland and forest associations; July 21, 1920, 8:10-11:10 A.M.; the day clear, hot; distance travelled about 6 miles, on foot, from Dudley northeast over ridge, thence down a canon to Smith Creek and back up to Dudley.
Mountain Quail 11+
Western Mourning Dove 3
Modoc Woodpecker 1
Willow Woodpecker 1
Northern White-headed Woodpecker 1
California Woodpecker 5
E«d-shafted Flicker 6
Anna Hummingbird 2
Black Phoebe 3
Western Wood Pewee 13
Traill Flycatcher 5
Blue-fronted Jay 8
Interior California Jay 13
Western Meadowlark 1
California Purple Finch 4
California Linnet 9
Green-backed Goldfinch 8
Total: species 34, individuals 167+.
Western Lark Sparrow 2
Sierra Junco 1
Sacramento Spurred Towhee 4
Northern Brown Towhee 7
Pacific Black-headed Grosbeak 6
Western Tanager 8
Western Warbling Vireo 5
Cassin Vireo 1
Hutton Vireo 1
Black-throated Gray Warbler 1
Sierra Creeper 1
Slender-billed Nuthatch 5
Eed-breasted Nuthatch 1
California Bush-tit 8
Western Gnatcatcher 2
Western Robin 5
Western Bluebird 15
El Portal and vicinity, 2000 feet. Upper Sonoran Zone with few Transition Zone elements, riparian, chaparral, and blue-oak and golden-oak associations; April 27, 1916, 7:00-11:40 a.m. (actual census time 4 hours); clear, hot day, little or no wind; distance covered about 5 miles, all on foot, within 2 miles of the settlement.
Valley Quail 1
Willow (?) Woodpecker 3
California Woodpecker 6
Red-shafted Flicker 2
White-throated Swift 14
Ash-throated Flycatcher 12
Blue-fronted Jay 1
Interior California Jay 17
Bullock Oriole 4
California Linnet 1
Green-backed Goldfinch 23
Western Chipping Sparrow 10
Sacramento Spurred Towhee 13
Northern Brown Towhee 14
Pacific Black-headed Grosbeak 5
Lazuli Bunting 10
Northern Violet-green Swallow 5
Western Warbling Vireo 5
Cassin Vireo 3
California Yellow Warbler 3
Black -throated Gray Warbler 3
Dotted Canon Wren 2
San Joaquin Bewick Wren 3
Western House Wren 5
Plain Titmouse 4
California Bush-tit 7
Pallid Wrentit 4
Western Gnatcatcher 18
Western Robin 4
Total: species 29, individuals 202.
CENSUSES OF BIBDS
29
YosEMiTE Valley, altitude 4000 feet, Transition Zone, chaparral, meadow, forest and riparian associations. May 31, 1915, 2:00-6:00 p.m.; from Sentinel Hotel to LeConte Lodge, then across Stoneman Bridge and along Sequoia Lane, with many zig-zags to likely looking brush clumps or trees, or to run down doubtful songs.
Sharp-shinned Hawk 1
Western Belted Kingfisher 2
Modoc Woodpecker 1
California Woodpecker 4
Eed-shafted Flicker 2
White-throated Swift 2
Calliope Hummingbird 2
Western Wood Pewee 18-1-
Wright Flycatcher 1
Traill Flycatcher 6
Blue-fronted Jay 4
Brewer Blackbird 1
California Purple Finch 6
Pine Siskin 12-!-
Western Chipping Sparrow 16-f-
Sacraraento Spurred Towhee 4
Total: species 32, individuals 220-h.
Pacific Black-headed Grosbeak 12f
Lazuli Bunting 3
Western Tanager 8
Northern Violet-green Swallow 6+
Western Warbling Vireo 15-1-
Cassin Vireo 15-t-
California Yellow Warbler 20-1-
Audubon Warbler lOf
Hermit Warbler 6-1-
Tolmie Warbler 3
Sierra Creeper 1
Short-tailed Mountain Chickadee 2
Western Ruby-crowned Kinglet 4
Russet-backed Thrush 2
Sierra Hermit Thrush 1
Western Robin 30-1-
YosEMiTE Valley, 4000-4500 feet, Transition Zone, forest, golden-oak and boulder- talus associations; June 3, 1915, 7:00-11:00 a.m.; clear day, windy; distance traveled about 8 miles, all on foot, from old Presidio down nearly to base of El Capitan and return, on Valley floor and up talus to base of cliff.
Band-tailed Pigeon 10
California Woodpecker 4
White-throated Swift 2
Western Wood Pewee 12
Traill Flycatcher 3
Western Flycatcher 1
Blue-fronted Jay 10
California Purple Finch 4
Pine Siskin 12
Western Chipping Sparrow 24
Sierra Juneo 4
Sacramento Spurred Towhee 2
Pacific Black-headed Grosbeak 8
Lazuli Bunting 2
Western Tanager 10
Total: species 30, individuals 186.
Western Warbling Vireo 12
Cassin Vireo 12
Calaveras Warbler 8
California Yellow Warbler 10
Audubon Warbler 2
Hermit Warbler 2
Black-throated Gray Warbler 4
Tolmie Warbler 1
Dotted Canon Wren 2
Sierra Creeper 1
Red-breasted Nuthatch 1
Short-tailed Mountain Chickadee 2
Russet-backed Thrush 1
Sierra Hermit Thrush 2
Western Robin 18
30
ANIMAL LIFE IN THE TOSEMITE
YosEMiTE Valley, 4000 feet, Transition Zone, forest, golden-oak, talus and chaparral associations; July 30, 1915, 7:30-10:00 a.m. ; along north side of Valley from old Presidio to vicinity of Kocky Point and return; distance traveled about 4 miles.
Band-tailed Pigeon 4
Red-shafted Flicker 1
Western Wood Pewee 8
Western Flycatcher 1
Blue-fronted Jay 2
California Purple Finch 1
Western Chipping Sparrow 12
Sacramento Spurred Towhee 2
Pacific Black-headed Grosbeak 2
Total: species 17, individuals 56.
Western Tanager 2
Western Warbling Vireo 3
Cassin Vireo 2
Black -throated Gray Warbler 5
Dotted Canon Wren 3
Sierra Creeper 2
Short-tailed Mountain Chickadee 4
Pallid Wren tit 2
YoSEMiTE Valley, 4000 feet. Transition Zone, forest, chaparral and riparian associa- tions; October 25, 1915, 2:35-5:35 p.m.; afternoon to late dusk of evening; weather clear; distance traveled about 6 miles, from old Presidio along north road to Kenney- ville, to Camp Curry, to village, to Presidio, then to Ahwahnee footbridge and return.
American Sparrow Hawk 1
California Pigmy Owl 3
Western Belted Kingfisher 2
Willow Woodpecker 1
California Woodpecker 6
Eed-shafted Flicker 4
Blue-fronted Jay 12
Golden-crowned Sparrow 1
Sierra Junco 12
Total: species 18, individuals 100.
Audubon Warbler 6
American Dipper 2
Sierra Creeper 2
Short-tailed Mountain Chickadee 1
W^estern Golden-crowned Kinglet 11
Western Euby-crowned Kinglet 1
Hermit Thrush (Alaska?) 2
Western Robin 10
Western Bluebird 23
YoSEMiTE Valley, 4000 feet. Transition Zone, ciiefly in forest association; Decem- ber 10, 1914, 7:50 A.M.-12:10 P.M.; eight inches of fresh snow on ground, and snow falling oflf and on during the morning; trees heavily laden with snow; from village via Camp Curry and Clark Bridge to Mirror Lake and up lower zigzags on Tenaya Lake trail, returning by same route.
California Pigmy Owl 1
Modoc Woodpecker 4+
Red-shafted Flicker 1
Blue-fronted Jay 1
Dotted Canon Wren 1
Total: species 10, individuals 26-1-.
Sierra Creeper 4
Short-tailed Mountain Chickadee 2
Hermit Thrush (Alaska!) 1
Western Robin 2
Western Bluebird 9-f-
YOSEMITE Valley, 4000 feet, Transition Zone, forest and riparian associations; February 29, 1916, 1:30-3:00 P.M.; about 3 feet of snow on ground; distance covered about 2 miles, west of village in vicinity of Camp Ahwahnee.
Duck 1
Western Belted Kingfisher 1
Sierra Junco 15)
American Dipper 1
Sierra Creeper 3
Total: species 9, individuals 52+.
Red-breasted Nuthatch 3
Short-tailed Mountain Chickadee 2
Western Golden crowned Kinglet 25-f
Townsend Solitaire (t) 1
CENSUSES OF BIEDS
31
YosEMiTE Valley, 4000 feet, Transition Zone, forest, meadow, chaparral and riparian associations; April 29, 1916, 7:10-10:55 a.m. (actual census time 3 hours 30 minutes); a bright day with few thin clouds and slight wind; distance covered 8 miles, from village to Yosemite Falls Camp, to El Capitan bridge, and return to village.
Mountain Quail 1
Red-shafted Flicker 4
White-throated Swift 1
Calliope Hummingbird 1
Wright (?) Flycatcher 5
Blue-fronted Jay 10
California Purple Finch 7
Sierra Crossbill (?) 2
Pine Siskin 22
Western Chipping Sparrow 35
Sierra Junco 25
Sacramento Spurred Towhee 6
Pacific Black-headed Grosbeak 11
Total: species 26, individuals 294.
Western Warbling Vireo 33
Cassin Vireo 29
Calaveras Warbler 3
California Yellow Warbler 13
Audubon Warbler 13
Hermit Warbler 31
Golden Pileolated Warbler 1
Sierra Creeper 7
Eed-breasted Nuthatch 3
Short-tailed Mountain Chickadee 2
Western Golden-crowned Kinglet 3
Western Euby-crowned Kinglet 6
Western Robin 20
Crane Flat to Merced Grove Big Trees, 6000-5500 feet, Canadian and Transition zones, coniferous and oak forest, meadow and riparian associations; June 15, 1915 7:30-11:00 A.M.; the day clear and hot; distance traveled about 4 miles, in more or less direct course between the two stations but with many short side trips to examine 'unknowns' or to study rare species.
Mountain Quail 4
Sierra Grouse 1
Sierra Red-breasted Sapsucker 1
Red-shafted Flicker 1
Calliope Hummingbird 3
Olive-sided Flycatcher 5
Western Wood Pewee 5
Hammond (?) Flycatcher 5
Western Flycatcher 1
Blue-fronted Jay 3
California Evening Grosbeak 2
Pine Siskin 3-1-
Western- Chipping Sparrow 10-1-
Sierra Junco 20-F
Mariposa Fox Sparrow 8
Green-tailed Towhee 5
Western Tanager 6
Total: species 33, individuals 149-I-.
Western Warbling Vireo 6
Cassin Vireo l
California Yellow Warbler 8
Audubon Warbler 3
Black-throated Gray Warbler 5
Hermit Warbler 3
Golden Pileolated Warbler 1
Western Winter Wren 1
Sierra Creeper 8
Red-breasted Nuthatch 4
Pigmy Nuthatch (?) flock
Short -tailed Mountain Chickadee 8
Western Ruby-crowned Kinglet 5-1-
Russet-backed Thrush 1
Sierra Hermit Thrush 2
Western Robin lO-t-
BiG Oak Flat Road below Gentrys, 4500-5700 feet. Transition Zone, golden-oak, talus, yellow-pine, and chaparral associations; December 28, 1914, 9:40 a.m.-1:30 p.m.; the day clear, crackling cold, trees covered with frost, snow on ground; distance traveled about 4 miles.
Golden Eagle 2
Blue-fronted Jay I
Sierra Junco 14+
Hutton Vireo 2
Dotted Canon Wren 3
Total: species 10, individuals 218-f.
Western Ruby-crowned Kinglet 1
Townsend Solitaire 42-(-
Hermit Thrush (Alaska?) 2
Northern Varied Thrush 8-t-
Western Bluebird 143-1-
32
ANIMAL LIFE IS THE YOSEMITE
Chinquapin and below, along Indian Creek, (5200 to 4500 feet, Canadian and Tran- sition zones, forest association chiefly; June 11, 1915, 7:;^0-ll:30 a.m.; distance covered about 7 miles, going and returning along different routes.
Mountain Quail 6
Sharp-shinned Hawk 1
Northern White-headed Woodpecker 1
Calliope Hummingbird 1
Olive-sided Flycatcher 2
Western Wood Pewee 4
Wright Flycatcher 10-f
Blue-fronted Jay 4-f-
Purple Finch (species?) 2
Sierra Junco 18
Mariposa Fox Sparrow 12-1-
Pacific Black-headed Grosbeak 2
Total: species 23, individuals 116-I-.
Western Tanager 6
Western Warbling Vireo 8-t-
Cassin Vireo 1
Calaveras Warbler 10-f
Audubon Warbler 2
Hermit Warbler 5
Golden Pileolated Warbler 2
Sierra Creeper 8-f-
Red-breasted Nuthatch 8-f-
Sierra Hermit Thrush 2
Townsend Solitaire 1
Chinquapin to Mono Meadow along "Glacier Point road," 6200-7700 feet, Canadian Zone, forest, riparian and chaparral associations; June 18, 1915, 7:20-10:30 a.m.; distance covered about 8 miles.
Mountain Quail 2
Northern White-headed Woodpecker 2
Northern Pileated Woodpecker 2
Olive-sided Flycatcher 3
Wright Flycatcher 10
Blue-fronted Jay 6
Cassin Purple Finch 4
Pine Siskin 1
Western Chipping Sparrow 8
Sierra Junco 30
Northeastern Lincoln Sparrow 8
Mariposa Fox Sparrow 10
Total: species 24, individuals 148.
Green-tailed Towhee 2
Pacific Black -headed Grosbeak 1
Western Tanager 6
Western Warbling Vireo 4
Audubon Warbler 6
Tolmie Warbler 2
Golden Pileolated Warbler 7
Sierra Creeper 2
Red-breasted Nuthatch 4
Short-tailed Mountain Chickadee 6
Western Ruby-crowned Kinglet 10
Western Robin 12
Above YOSEMITE Falls, 6600-7300 feet, Canadian Zone, chaparral and forest associa- tions- October 30, 1915, 10:20 a.m.-4:20 p.m.; distance traveled about 5 miles, from top of zigzags, along old Snow Flat trail to west branch of Indian Canon, and return.
Cooper Hawk 1
Western Red-tailed Hawk 2
Modoc Woodpecker 1
Northern Pileated Woodpecker 1
Red-shafted Flicker 2
Blue-fronted Jay 22
Clark Nutcracker 1
California Evening Grosbeak 4
Cassin Purple P"'inch 4
Golden-crowned Sparrow 1
Total: species 20, individuals 106.
Kadiak Fox Sparrow 5
Sacramento Spurred Towhee 1
Red-breasted Nuthatch 14
Slender-billed Nuthatch 2
Short-tailed Mountain Chickadee 20
Western Golden-crowned Kinglet 3
Townsend Solitaire 13
Western Robin 4
Northern Varied Thrush 3
Western Bluebird 2
CENSUSES OF BIRDS
33
Tioga Road between Porcupine Flat and Snow Flat, and return, 8100 to 8700 feet, across Canadian-Hudsonian Zone boundary, forest and meadow associations; June 28, 1915, 6:55 a.m. to 1:45 p.m. (actual census time 5 hours 45 minutes); clear, moderately warm, much snow about, covering road in places; distance covered about 6 miles, by two observers jointly.
Mountain Quail 4
Sierra Grouse 2
Modoc Woodpecker 1
Williamson Sapsucker 4
Red-shafted Flicker 1
Olive-sided Flycatcher 3
Western Wood Pewee 8
Blue-fronted Jay 5
Clark Nutcracker 4
Cassin Purple Finch 3
Pine Siskin 18
Western Chipping Sparrow 9
Sierra Junco 12
Northeastern Lincoln Sparrow 1
Total: species 28, individuals 164.
Mariposa Fox Sparrow 5
Green-tailed Towhee 2
Western Tanager 6
Western Warbling Vireo 7
Audubon Warbler 9
Golden Pileolated Warbler 3
Sierra Creeper 3
Red-breasted Nuthatch 8
Short-tailed Mountain Chickadee 9
Western Golden-crowned Kinglet 7
Western Ruby-crowned Kinglet 14
Townsend Solitaire 1
Sierra Hermit Thrush 9
Western Robin 6
Meeced Lake, 7500 feet, Canadian Zone, forest and riparian associations; August 20, 1915, 8:00-10:30 a.m.; distance traveled about 2 miles, all within one mile of upper end of lake.
Red-shafted Flicker 1
Hammond Flycatcher 2
Blue-fronted Jay 2
Sierra Junco 8-1-
Mariposa Fox Sparrow 1
Western Warbling Vireo 2
Total: species 12, individuals 30-I-.
Cassin Vireo 2
Calaveras Warbler 2
Audubon Warbler 2
Red-breasted Nuthatch 2
Short-tailed Mountain Chickadee 4
Western Ruby-crowned Kinglet 2
Vogelsang Lake to Evelyn Lake and return, via Fletcher Creek, 10,350 feet, Hud- sonian Zone, rock-slide, riparian and white-bark pine associations; September 4, 1915, 7:30 A.M.-12:30 p.m. (but actual census time 4 hours) ; heavy frost in morning, ice on quiet pools; distance traveled about 5 miles.
Western Mourning Dove 1
Prairie Falcon 1
Blue-fronted Jay 1
Clark Nutcracker 7
Hudsonian White-crowned Sparrow .. 7-1-
Sierra Junco 10
Total: species 11, individuals 50-I-.
Lutescent Warbler 1
Audubon Warbler 14
American Dipper 3
Short -tailed Mountain Chickadee 4
Western Gnatcatcher 1
Glen Aulin, 7700 feet, Hudsonian-Canadian Zone boundary, riparian and forest associations; September 30, 1915, 9:15 A.M.-12:15 p.m.; clear, moderately warm in sun- light, west wind; distance covered about 4 miles, in territory northeast of the Glen.
Western Belted Kingfisher 1
Red-shafted Flicker 4
Blue-fronted Jay 3
Clark Nutcracker 5
Sierra Junco 15-t-
Total: species 10, individuals 86+.
Audubon Warbler 8
American Dipper 1
Short -tailed Mountain Chickadee 24
Townsend Solitaire 23
Western Robin 2
34
ANIMAL LIFE IN THE TOSEMITE
Tuolumne Meadows, 8600 feet, Hudsonian Zone, forest, riparian and meadow associations; July 7, 1915, 8:00-10:00, 11:00-11:45 a.m.; clear, sunny, warm; distance traveled about 4 miles, chiefly along road on south side of meadows.
Spotted Sandpiper 3
Killdeer 2
Pacific Nighthawk 2
Western Wood Pewee 8
Cassin Purple Finch 4
Pine Siskin 11
Hudsonian White-crowned Sparrow.. 11 Western Chipping Sparrow 2
Total: species 16, individuals 80.
Sierra Junco 11
Green-tailed Towhee (f) 1
Audubon Warbler 3
Short-tailed Mountain Chickadee 2
Western Ruby-crowned Kinglet 3
Sierra Hermit Thrush 1
Western Bobin 12
Mountain Bluebird 4
Young Lake (near Conness Mountain) to Tuolumne Meadows, 10,000-8600 feet, Hudsonian Zone, forest, meadow and rock-slide associations; 8:30 a.m.-12:30 p.m., July 9, 1915; clear, hot, slight westerly wind; distance covered about 7 miles.
Golden Eagle 1
Western Wood Pewee 4
Wright (?) Flycatcher 1
Clark Nutcracker 7
Cassin Purple Finch 12
Pine Siskin 10
Hudsonian White-crowned Sparrow .. 1
Western Chipping Sparrow 1
Total: species 16, individuals 87.
Sierra Junco 18
Audubon Warbler 4
Rock Wren 4
Short-tailed Mountain Chickadee 8
Western Ruby-crowned Kinglet 3
Sierra Hermit Thrush 4
Western Robin 4
Mountain Bluebird 5
Warren Fork of Leevining Creek, 9200-11,000 feet, upper part of Hudsonian Zone, open forest and cliff associations, chiefly; September 26, 1915, 7:10 a.m.-2:30 p.m.; after slight snowstorm on September 25, partially clear day; distance covered about 10 miles, from camp in canon up onto Tioga Crest, thence around head of canon to southwest slope of Warren Mountain, and return.
Sierra Grouse 8+
Hawk (unidentified) 1
Owl (probably Horned) 1
Modoc Woodpecker 1
Williamson Sapsiicker 2
Red-shafted Flicker 3
Clark Nutcracker 45f
Cassin Purple Finch 11-1-
Sierra Nevada Rosy Finch 16
Sierra Junco 59-1-
American Pipit 2
American Dipper 2
Short-tailed Mountain Chickadee 21-t-
Mountain Bluebird 11
Total: species 14, individuals 183-I-.
CENSUSES OF BIBDS
35
Pabrington Kanch to Walker Lake and return, 6600-8000 feet, Transition and Can- adian zones, meadow, riparian and sagebrush associations; May 9, 1916, 2:00-7:00 P.M.; strong west wind; distance traveled about 12 miles, returning through sagebrush on ridge adjacent to Williams Butte.
California Gull 1
Mountain Quail 1
Sierra Grouse 3
Western Mourning Dove 16
American Sparrow Hawk 1
Long-eared Owl 1
Eed-shafted Flicker 3
Lewis Woodpecker 2
Traill (?) Flycatcher 1
Black -billed Magpie 2
Blue-fronted Jay 1
Clark Nutcracker 6
Nevada Red-winged Blackbird 25
Western Meadowlark 7
Total: species 28, individuals 119.
Western Vesper Sparrow 2
Nevada Savannah Sparrow 8
Hudsonian White-crowned Sparrow .. 5
Brewer Sparrow 2
Sierra Junco 4
Modoc Song Sparrow 2
Mono Fox Sparrow 1
Green-tailed Towhee 1
Western Tanager 1
Audubon Warbler 4
Alaska Pileolated Warbler 1
Western House Wren 1
Western Robin 13
Mountain Bluebird 4
Farrington Ranch (near Mono Lake) to Mono Craters and June Lake, and return; Transition and Canadian zones, sagebrush, Jeffrey -pine and meadow associations; Sep- tember 17, 1915, 7:50 a.m.-6:50 p.m.; distance covered about 25 miles, on horseback.
Mud-hen lOO-t-
Marsh Hawk 1
Large Hawk (Red-tailed?) 1
American Sparrow Hawk 1
Eed-shafted Flicker 1
Say Phoebe 1
Dusky Horned Lark 14+
Clark Nutcracker 18-1-
Pinon Jay 51+
Western Meadowlark 1
Brewer Blackbird 106+
California Linnet 6
Western Vesper Sparrow 8-'-
Total: species 25, individuals 478+.
Intermediate White-crowned Sparrow 3+
Brewer Sparrow 107+
Small sparrows (Spisella) 3
Nevada Sage Sparrow 10
Green-tailed Towhee 12
Audubon Warbler 4
Sage Thrasher 7
Sierra Creeper 1
Slender-billed Nuthatch 9+
Pigmy Nuthatch 1+
Short-tailed Mountain Chickadee 11+
Mountain Bluebird 1
Mono Lake Post Office and vicinity, Transition Zone, willow-cottonwood, meadow and sagebrush associations; May 31, 1916, 7:00 a.m.-12:00 m.; weather bright and warm; distance traveled about 2^/^ miles, chiefly along lake shore.
American Eared Grebe 50
California Gull 13
Black-chinned Hummingbird 1
Western Kingbird 2
Western Wood Pewee 14
Traill Flycatcher 14
Nevada Cowbird 3
Nevada Red-winged Blackbird 22
Western Meadowlark 6
Brewer Blackbird 16
Nevada Savannah Sparrow 1
Western Lark Sparrow 1
Hudsonian White-crowned Sparrow .. 4 Brewer Sparrow 2
Total: species 27, individuals 293.
Modoc Song Sparrow 13
Green-tailed Towhee 2
Pacific Black-headed Grosbeak 3
Lazuli Bunting 1
Rocky Mountain Orange-crowned
Warbler 4
Yellow Warbler 34
Townsend Warbler 2
Tolmie Warbler 4
Western Yellowthroat 3
Pileolated Warbler 57
Western House Wren 3
Western Robin 13
Mountain Bluebird 5
36 ANIMAL LIFE IN THE YO SEMITE
THE INTERRELATIONS OF LIVING THINGS
That forests afford the means of existence for a great number of animals, with reference to both species and individuals, is a trite statement which no one is likely to question. We would offer, however — albeit with some caution — a second statement : Forests depend, for their maintenance in the condition in which we observe them in this age of the world, upon the activities, severally and combined, of the animals which inhabit them.
Beginning at the root of the matter, in a double sense, as we have emphasized beyond in the chapter on the pocket gophers, mammals which burrow are of importance to forests. The pocket gophers, the ground squirrels, the moles and the badgers, are natural cultivators of the soil (see p. 142), and it is, in considerable degree, the result of tiieir presence down through long series of years that the ground has been rendered suit- able for the growth of grasses and herbs, and even of bushes and trees, particularly in their seedling stages, A host of insects, also, which live in the ground at least part of their lives, contribute to rendering the soil more productive of vegetable life.
Vegetable materials^ leaves, twigs and trunks of trees as well, contribute to soil accretion by reason of their being torn to pieces by animals (see p. 322), their particles scattered by animals, and these finally overlaid by the earth brought up by animals from deeper substrata. The animals which figure conspicuously in this process are the woodpeckers, chickadees, and nuthatches, the tree squirrels, chipmunks, and porcupines, the burrowing beetles, the termites, and the ants, and then the burrowing and burying mammals already referred to. This process of incorporating humus into the soil, accomplished in large measure by animals, is of direct and lasting importance to the forests.
We do not make any claim that oil animal life is directly beneficial to the forests. For many insects may be seen to feed upon the foliage, the bark, and even the live wood of individual trees, and in so doing such insects shorten the lives of these trees, or even sometimes kill them outright within a single season. It is obvious that a sudden overabundance of such destructive insects would bring serious injury to the forests.
But observation has led us to recognize, in certain groups of hlvdn, natural checks to undue increase of forest-infesting insects. Insects of one category inhabit the bark of a tree or the layers of wood immediately beneath ; others pursue their existence among the smaller twigs ; still others
INTEBBELATIONS OF LIVING THINGS 37
live amid the foliage of the tree. In all these cases the substance of the tree is levied upon by the insects for food, and if levied upon unduly, the trees suffer commensurately. But, as counteracting factors, we find corre- sponding categories of birds, each specially equipped to make use of one of these categories of insects. The woodpeckers, nuthatches, and creepers search the tree trunks and larger limbs; the chickadees comb the finer twigs ; while the kinglets and warblers go over the foliage leaf by leaf. The great value of the bird to the tree comes when the harmful insects have begun to multiply abnormally ; for birds are well known to turn from other food sources and concentrate upon the one suddenly offering in generous measure.
It is to the interest of the forest at large that a reserve nucleus of birds be maintained constantly, as a form of insurance, to be ready at just such a critical time. Incursions of insects from neighboring areas, as well as eruptions of endemic species, have probably occurred again and again from remote times. In other Avords, as we see the situation, it is an advantage to the forest that a continual moderate supply of insects be maintained for the support of a standing army of insectivorous birds, which army will turn its attention to whatever insect plague happens suddenly to manifest itself.
We would claim, then, a nice interdependence, an adjustment, by which the insect and the bird, the bird and the tree, the tree and the insect, all are, under average circumstances, mutually benefited. Such a balance is to be found in the primeval forest, where thoroughly 'natural' conditions obtain as a result of long ages of evolution on the part of all the animate things there touching upon one another's lives. These relations may, of course, be entirely upset where man has interfered, directly or indirectly ; as, for instance, when he brings in insects or plants alien to the original fauna and flora. Then an entirely new program, one of readjustment, begins.
After a good deal of study, and contemplation of the modes of life of various kinds of animals, naturalists have come to recognize as essential three factors which seem inseparably bound up with the successful existence of any one species of vertebrate animal. These factors are: (1) presence of safe breeding places, adapted to the varying needs of the animal; in other words, depending upon the inherent powers of construction, defense, and concealment in the species concerned. (2) Presence of places of temporary refuge for individuals, during daytime or night-time, or while foraging, when hard pressed by predatory enemies, again correlated with the inherent powers of defense and concealment of the species involved. (3) Kind of food supply afforded, with regard, of course, to the inherent structural powers in the animal concerned to make it available.
38 ANIMAL LIFE IN THE YOSEMITE
To say all this a bit more simply, not alone food is necessary to the bird life or the mammal life in our forests, but also safe places for rearing young, and places of refuge when needed, for the grown-up individuals themselves. Referring again to the relationships borne between certain insects, birds, and trees: The White-headed Woodpecker (see p. 320) is a species which does practically all of its foraging on trees which are living, gleaning from them a variety of bark-inhabiting insects. But the White- headed Woodpecker lacks an effective equipment for digging into hard wood. It must have dead and decaying tree trunks in which to excavate its nesting holes. If, by any means, the standing dead trees in the forests were all removed at one time, the White-headed Woodpecker could not continue to exist past the present generation, because no broods could be reared according to the inherent habits and structural limitations of the species. Within a woodpecker generation, the forests would be deprived of the beneficent presence of this bird. The same, we believe, is true of certain nuthatches and of the chickadees — industrious gleaners of insect life from living trees. They must have dead tree trunks in which to establish nesting and roosting places, safe for and accessible to birds of their limited powers of construction and defense.
We would go so far, even, as to urge that down timber, fallen and decay- ing logs, are essential factors in upholding the balance of animal life in forests. Certain kinds of chipmunks, and rats and mice of various kinds, find only in fallen logs homes adapted for their particular ways of living. And these chipmunks and other rodents have to do with seed scattering, with seed planting, and with humus building, again directly affecting the interests of the chaparral, of the young trees, and even of the older trees of the forest.
It is true that there are some kinds of birds and mammals which at times directly injure trees to an appreciable extent. The birds of the genus of woodpeckers called sapsuekers (see p. 327) drain the vitality of the trees they attack. An overabundance of these birds would bring disaster to the forest at large. An overabundance, likewise, of tree squirrels (see pp. 202, 208) would probably play havoc with certain trees, beyond the powers of these trees to meet the crisis.
Just as in the case of the leaf-eating insects and of the kinglets in the arboreal foliage, these birds and mammals of the sapsucker and tree- squirrel category are kept in check by other, predatory birds and mammals. In the Sierran woods are Great Gray Owls and Spotted Owls, Cooper Hawks, Martens, and Weasels, levying upon the vertebrate life about them, and each equipped by size, degree of alertness, or time of foraging, to make use of some certain sort of prey. The longer we study the problem the clearer it becomes that in the natural forests, which, happily, are being
INTEEEELATIONS OF LIVING THINGS 39
preserved to us in our National Parks, a finely adjusted interrelation exists, amounting to a mutual interdependence, by which all the animal and plant species are within them able to pursue their careers down through time successfully.
The opportunity here to moralize is tempting. If the above course of reasoning be well founded, then, to realize, esthetically and scientifically, the greatest benefit to ourselves from the plant and animal life in Yosemite Park, its original balance must be maintained. No trees, whether living or dead, should be cut down beyond what it may be necessary to remove in building roads or for practical elimination of danger, locally, from fire. Dead trees are in many respects as useful in the plan of nature as living ones, and should be just as rigorously conserved. When they fall, it should be only through the natural processes of decay. The brilliant- hued woodpeckers that render effective service in protecting the living trees from recurrent scourges of destructive insects, in other words, in keeping up the healthy tone of the forest, depend in part on the dead and even the fallen trees for their livelihood.
No more undergrowth should be destroyed anywhere in the Park than is absolutely necessary for specific purposes. To many birds and mammals, thickets are protective havens which their enemies find it difficult or impossible to penetrate. Moreover, the majority of the chaparral plants are berry-producing and give sustenance to mountain quail, to wild pigeons, to robins and thrushes, to chipmunks and squirrels, and this, too, at the most critical times of the year when other foods for these animals are scarce or wanting. The removal of any of these elements would inevitably reduce the native complement of animal life. Nor do we approve, as a rule, of the destruction of carnivorous animals — hawks, owls, foxes, coyotes, fur-bearers in general — within the Park. Each species occupies a niche of its own, where normally it carries on its existence in perfect harmony on the whole with the larger scheme of living nature.
40 ANIMAL LIFE I\ THE YOSEMITE
ACCOUNTS OF THE SPECIES
Scope
In the chapters to follow, dealing with the three hundred and fifty-five kinds of terrestrial vertebrate animals in the Yosemite section, general uniformity of treatment has been one aim. For each species there is given, first, the accepted or approved vernacular name; then the scientific name, chosen with regard to the best technical usage. The order in which the chapters follow one another is essentially that in which the species are classified in the standard lists of North American vertebrates; namely, for mammals, Miller's List of North American Land Mammals in the United States National MiLseum, 1911; for birds, the American Ornithologists' Union Check-list of North American Birds, edition 3, 1910 ; and for reptiles and amphibians, Stejneger and Barbour's Check List of North American Amphibians and Reptiles, 1917. Departures from these authorities, either in sequence or in names employed, have been made occasionally by us, but only when justified by special study.
The present volume is not a systematic treatise in the sense of relating primarily to descriptive zoology or to cla.ssification. Hence, technicalities along these lines are reduced to a minimum, being mentioned briefly, or restricted to small-type footnotes. The theme of the pn^ent book is udfural history — that which relates to the living animal.
The "field characters" are intended to include the chief features by which each species may be recognized out of doors. They do not have to do with the scientific 'specimen,' such as constitutes the basis of the usual descriptive account. Tdeallj^ our "field characters" are such as are dis- cernible in the living animal at the ordinary eye-range into which a person can approach the animal under normal conditions. The great majority of these characterizations have been derived from our own observations in the Yosemite region, as recorded in our notebooks. Exceptionally, we have drawn upon our experience elsewhere; or, in the few cases where experience was lacking altogether, we have drawn u])on specimens for characters inf<'rred to be useful in Ihe field.
In small mamnuils and in replilcs and jiinphihiaiis. ihc Held character- ization has been amplified to cover their appeai-iuu'e and proportions when in hand; for opportunity to capture these animals often jiresents itself to an out-of-doors observer. Even in these cases, however, it is exclusively
SCOPE OF THE ACCOUNTS 41
the external, macroscopic features of the animal that are set forth in the paragraph on ''field characters."
Field characters may consist in relative size, in proportions of parts,' in general color tone, in pattern of contrasted markings, in peculiarities of movement (flight, gait, mannerisms), in voice, and, with many mammals, in 'sign' (foot-prints, tooth-marks, droppings). Measurements are given, more especially with mammals, and are stated as a rule in both inches and millimeters. Otherwise, size is indicated by comparison with some animal commonly familiar. Since size impressions in the field are likely to asso- ciate themselves in memory with the best known animals, comparisons among birds are most often made with the robin; among mammals, with the house mouse, house rat, or house cat.
Our paragraph on "occurrence" relates explicitly to the Yosemite section. The status we give of each species is as based on actual findings in the Yosemite section, not upon inference from conditions in the sur- rounding territory. It must not be supposed to apply to the Sierras gen- erally or to any larger area. "Occurrence" is intended to cover concisely the concepts: season, relative abundance, and distribution by geography, life zones, and vegetational tracts.
In the general, large-type account next following, there will often be found one or more paragraphs discussing some or all of the field characters, especially in comparison with similar species with which confusion in the field might occur. In some cases, characters are discussed with relation to the distinctive habits of the species in question ; in other words, corre- lation of structure and function may be dealt with.
But, let it be emphasized by repetition that, save for only occasional general statements, each account is limited to what was found out by us in the Yosemite region. This will explain the very uneven magnitude of the accounts. Their relative degree of comprehensiveness merely reflects our own varying opportunities of observation. A number of well-known species of the Sierras at large are given but meager attention here because opportunity did not present itself for studying them adequately in the Yosemite 'section.'
Each general account, where the facts have been fully available, has been drawn up, with regard to its subject-matter, on a more or less definite plan of presentation. An introductory paragraph gives local names, other than the accepted vernacular, and an epitome of the leading facts about the species. Comparisons with related species are then made. There follows a discussion of its distribution in the Yosemite region and the special nature of its habitat preferences. Then comes a description of the animal 's behavior ; its voice ; nests, or dens ; eggs, or young ; care of young ; and its feeding habits. We give as much as we have learned with respect
42 ANIMAL LIFE IX THE YO SEMITE
to the food of the species, and its relation to plant life in general ; also, its relation to other animals, as predator or victim. And, finally, though not appearing at any definite point in the account, we attempt to point out where general biological principles are illustrated.
The facts observed have been gathered together in orderly sequence, and every effort has been made to secure accuracy of expression. Where these facts, thus assembled, point toward some generalization, we have felt free to set it forth. At the same time, we have tried to refrain from idle speculation.
The study of natural history should develop the power of insight — keenness, not only in seeing what animals do, but in determining why those things are done. The interrelations existing between any animal and its environment are exceedingly manifold and vital. To understand these, even in some small degree, brings into play a superior type of intellectual activity, and, we believe, leads to enhanced powers of perceiving and solving human problems. We therefore recommend to the reader that he take advantage of his opportunities to observe and infer without limit beyond whatever we may have set forth herein, to the end that he find both pleasure and profit.
THE MAMMALS
Moles. Scapanus latimanus (Bachman)^
Field characters. — Total length 6 to 6% inches (150-170 mm.), tail about IVz inches (38 mm.); body short and cylindrical; snout long and pointed (fig. 4); forefeet with greatly expanded and flattened palms and long heavy claws (fig. 5a) ; tail scantily and coarsely haired; no eyes or ears visible. Pelage short, soft, plush-like in texture; coloration uniform, dark brown, gray, or blackish (accord- ing to subspecies), appearing silvery when smoothed down. Habits: Strictly subterranean; live in tunnels formed by the animals themselves in the ground. Workings: Low raised ridges (containing runways) along the surface of ground; also, less commonly, mounds of earth mth irregu- lar surface, erupted from underground tunnels, and with no indication left of any opening to burrow (fig. 22).
Occurrence. — Present in small to moderate numbers locally across the Yosemite region; noted from Snelling eastward to Mono Mills and up to an altitude of 9500 feet (in Lyell Caiion) ; especially common in meadows of Yo- semite Valley.i Individuals live and work independently.
Fig. 4. Snout of Yo- semite mole, from below, showing elongate tip be- yond mouth, short front (incisor) teeth, and heavy covering of hairs on sides of face. Twice natural size.
The mole and the pocket gopher, and the re- spective workings of the two, are often confused in the popular mind. The two animals, and their workings, however, are entirely distinct in practically all respects save that both inhabit the ground. In most places in California, and this includes the Yosemite region, moles are much less common than gophers. This fact probably accounts for some of the misunderstanding which has arisen. By careful searching we found some evidence of moles at almost every locality which we visited in the section (below the 9500 foot contour) from the San Joaquin Valley eastward across the mountains to Mono Lake. On the floor
1 Three slightly differing subspecies of moles occur in the Yosemite section. These, with their principal external characters, and ranges, are as follows :
Yosemite Mole, Scapanus latimanus sericatus Jackson, distinguished by relatively large size and blackish coloration, is found in the Transition and Canadian zones, spar- ingly in the Hudsonian, from 3 miles east of Coulterville eastward to Tuolumne Meadows. It is abundant in Yosemite Valley.
San Joaquin Mole, Scapanus latimanus campi Grinncll and Storer, a smaller, paler and more brownish colored form, occurs in the Lower Sonoran Zone, at Snelling.
Mono Mole, Scapamis latimanus monoensis Grinnell, a still smaller and grayish-toned subspecies, was found near Williams Butte; its workings were noted at Mono Mills.
The workings of these three races are alike in all respects, save for differences con- ditioned by the various sorts of ground in which they occur. Thus the forage runways of monoensis in the dry sandy soil of the Mono Lake region are more likely to be caved in than are those of sericatus on the damp forest floor in the mountains.
[43]
44 ANIMAL LIFE IN THE TOSEMITE
of Yosemite Valley there is an unusually large mole population, and, as gophers are present also in considerable numbers, the habits of the two may there be studied and compared to good advantage.
The mole is rather more strictly subterranean than the gopher. The latter animal is not infrequently seen at the mouth of its burrow, and occasionally it comes clear out on the top of the ground. The mole, how- ever, habitually stays below the surface. All of its foraging is done in the ground; even when excavating a burrow, the animal itself is not exposed to view from above. ^loles are said to run about on the surface of the ground at mating time, but of this we have no direct knowledge.
Fig. 5. Forefoot of (a) Yosemite Mole and of (b) Sierra Nevada Pocket Gopher. The Mole's palm is greatly expanded and the claws are relatively huge, which features together with powerful arm and shoulder muscles make it possible for the animal almost literally to swim through the earth ; the Gopher 's foot is less extreme, yet with elongated claws for special service in digging and with hairs between the toes which serve to increase the area of the foot when loose earth is being pushed out of or along the burrow. Natural size.
In physical configuration the mole is admirably suited for life under- ground (pi. 27c). Its nose is long and pointed and equipped with numerous fine sensory bristles. The mouth opens on the under side of the head where dirt is less likely to enter when the animal is burrowing. The head joins directly onto the firm stout cylindrical body without any constriction at the neck region. The body as a whole is an 'entering wedge.' The forelegs are extremely short so that the feet lie close along- side the head. The front feet are highly modified to form 'spades,' the palms being enlarged into thickened discs and turned outward, and the nails or claws being elongated and very stout. By means of these broad strong members the mole literally swims through the loose surface soil. The hind feet are much smaller and quite normal in shape and function. The body ends behind abruptly, and there is a short tail but scantily haired. The whole body of the mole is densely covered with short hairs of remark- ably uniform length and texture which give a silky plush-like effect to the pelage. This sort of coat enabh's the animal to pjtss tlirough the ground with a minimum of resistance; in oilier words, it acts as a lubricant.
The mole makes and uses two distinct sorts of underground passage- ways. One of these is the 'surface' runway, actually a subsurface run or subway, an inch or less below the top of the ground. The mole 'swims' along by strokes of the forefeet; its feet and body push flic soil up in a low
MOLES 45
ridge, leaving numerous small lengthwise cracks showing on the outside (pi. 28a). These runs go here and there along the ground, between rocks and beside logs; they are made when the mole is searching for the worms and ground-dwelling insects which it uses as food. The second type of shelter, formed by actual excavation as in a gopher's burrow, is a regular underground tunnel, circular in section, and situated at a greater depth in the ground. The mole's tunnels are not so extensive and are of less diameter than those of any of the gophers of the region. To make these deep burrows the mole must force the loosened earth out onto the surface of the ground. This it does through laterals constructed at short intervals. Earth is loosened below ground (by the use of the forefeet ?), then is forced along the existing tunnel way presumably by the joint use of forefeet and chin (though the actual method of operation has yet to be seen), and it is then forced up a lateral. As we stated before, there is never any direct opening to the exterior. Each fresh lot of earth is forced into the vertical or nearly vertical lateral, pushing the earth already there out on top of the ground to topple over in one direction or another (see pi. 28& and fig. 22). Because of this method of digging, there are usually six inches or so of earth between the mole and the outside world. The freshest earth forms a central 'core' in the molehill. This core, of whose position there is seldom any external indication, can often be distinguished if the mound be sectioned in a vertical plane.
Practically all of our specimens of moles were taken in special mole traps designed to be set over a surface runway, and the use of such traps gave some information concerning the use of these runways. Sometimes a trap set over a newly made runway would catch a mole within a few hours; in other instances the trap remained several days before being disturbed. These facts indicate that there is considerable variation in the frequency with which the surface runways, once made, are traversed. On still other occasions no reoccupation of the run was noted. After one mole was caught in a runway, another individual sometimes appropriated the vacated system to its own use. On November 18, for example, a mole was taken in a run on the forest floor of Yosemite Valley. On the nine- teenth the trap was sprung again, and being reset, caught a second mole on the twenty-first. It is believed that ordinarily but one individual inhabits a particular system of runways and tunnels at any one time.
Evidence of the activity of moles was found below the 5000-foot contour during every month of the year. In the summer and the fall months both surface runs and molehills indicative of deeper excavations were observed, in Yosemite Valley ; and at the end of December new runways were noted in places in the Valley where the ground was not frozen. During the height of winter in the high mountains when the ground is frozen to a
46 ANIMAL LIFE IN THE YOSEMITE
considerable depth, conditions would certainly seem unfavorable for active existence of moles. But whether or not those animals become dormant, as do the chipmunks, we do not know.
Though there is no one kind of territory save solid rock where moles are absent, more of their work is to be found in dryish moadowlands than elsewhere. One runway was found in the gravelly ground beneath the boulder talus along the base of the north wall of Yosemite Valley. The dry needle- and leaf-strewn ground of the forest floor is often extensively marked by surface runways. The concentration of moles in these places is undoubtedly due to the greater abundance and accessibility there of suitable food.
The breeding season of moles generally, in California, is in the early spring. A male captured at Snelling January 9, 1915, wa.s in breeding condition ; a nearly grown young male was collected at the same place on May 29, 1915. Two individuals collected on June 2, 1915, 3 miles east of Coulterville and in Yosemite Valley, respectively, were, to judge by the unworn condition of their teeth, animals born during the current season. Another juvenal mole was obtained 3 miles east of Coulterville on June 6. These data suggest that the breeding season at the levels indicated is early, probably just at the end of the winter months.
As already intimated the mole's diet consists almost exclusively of animal matter. In lowland districts, earthworms probably constitute a large portion of its fare. For example, the stomach of a mole trapped by one of our party at Snelling, January 9, 1915, contained "long sections of earthworms" together with some "dirt." As earthworms are relatively scarce or absent in the higher mountains the moles there must feed on other sorts of 'worms.' Elsewhere it is known that they eat the larvae of certain insects, such as cutworms (moth larvae), and it is probable that, in the higher mountains, too, such larvae form part of the mole's bill of fare.
A "Macabee" gopher trap set in a surface runway of a mole on the sandy 'second bottom' at El Portal on November 27, 1914, caught a mola during the night. When the trap was examined on the following morning the trapped mole had been completely defleshed, the skull was almost clean save for ligaments, and the skin was turned inside out leaving an almost perfect skeleton. This probably was the work of another mole, though there is the possibility that a shrew, following the mole's run, wjis responsible.
The mole, it will be seen from the above account, occupies a very diff(irent niche from that of the gopher. Yet the two inhabit the ground; and in their regular existence both promote in various ways the develop- ment of soil and, consequently, conditions that are favorable to plant growth. This principle has been set forth in detail in the chapter on the gopher. (See p. 141.)
SHBEWS 47
Shrews. Genus Sorex^
Field characters. — Size varying, but always less than half that of House Mouse. Head and body not over 3 inches (75 mm.) long, tail 2 inches (50 mm.) or less. Snout long and pointed (pi. 20); eyes and ears inconspicuous; pelage short, dense and smooth- appearing. Forefeet like hind feet, not specialized for digging. Coloration uniform, brown above (varying in tone according to the species), lighter, sometimes whitish, on under surface.
Occurrence. — Common from upper margin of Upper Sonoran Zone up to upper edge of Hudsonian Zone; recorded from Dudley, on Smith Creek (east of Coulterville), east- ward to vicinity of Mono Lake.2 (See fig. 6.) Live chiefly in damp situations along stream banks or in meadows, but sometimes found in protected situations at considerable distances from water.
Shrews are present in the Yosemite region in large numbers, yet because of their small size and secretive habits they are much less well known than are the majority of other small mammals, such as meadow mice. The shrews leave little or no visible evidence of their activity, and it takes much
2 Five species of true shrews (Genus Sorex) occur in the Yosemite region. The general appearance and the habits are much the same in all of these, though but little information other than that gained by trapping is available regarding their life histories. The species, their ranges, and their chief characters are as follows:
Dusky Shrew, Sorex oiscurus ohscurus Merriam, a wide-ranging species found both in the Eocky Mountains and in the Sierra Nevada south to Tulare County, is common in the Canadian and Hudsonian zones of the Yosemite region from Mono Meadow (near Glacier Point) and from East Fork of Indian Canon eastward to Warren Fork of Leevin- ing Creek and to Williams Butte. Extreme altitudes of capture w^ere 6900 and 10,800 feet. It lives not only along streams and in marshy places but also about logs on the forest floor. Total length about 4 to 4^^ inches, tail 1% inches, hind foot % inch (12.2-13.0 mm.); coloration dull sepia brown above, ashy on under surface. (See pi. 20c.)
Adorned Shrew, Sorex ornatus Merriam, is found in mountainous parts of southern California and on the lower west slope of the Sierra Nevada, from the Mexican boundary north to the Yosemite region. Locally it is common at El Portal, and one individual was taken at Dudley, 6 miles east of Coulterville. Lives both along streams and on hillsides covered with live oaks and brush. Total length 4 inches, tail 1% inches, hind foot about 14 inch (12-13.5 mm.). Coloration dull brown above, whitish beneath.
Yosemite Shrew, Sorex montereyensis mariposae Grinnell, lives in the Transition Zone and lower part of the Canadian Zone on the west flank of the Sierra Nevada. It was found from Sweetwater Creek and Merced Grove Big Trees eastward to East Fork of Indian Canon and to Merced Lake; it is the only shrew recorded for the floor of Yosemite Valley. Extreme altitudes of occurrence, 3800 and 7500 feet. It inhabits almost exclusively damp places near streams. Total length 4% to 5 inches, tail 2 inches, hind foot somewhat more than i/^ inch (14-15 mm.). Largest local shrew of the genus Sorex. Coloration mixed hair brown and drab gray above, drab gray below with a silvery sheen. (See pi. 20fe.)
Sierra Nevada Shrew, Sorex vagrans amoenus Merriam, of wide distribution along the northern Sierra Nevada, was found by us only at Williams Butte and Mono Lake Post Ofiice. Lives near streams or in meadows. Total length about 4 inches, tail usually less than 1^/^ inches, hind foot about ^o inch (11.5-13 mm.). Pelage sooty brown, grizzled with lighter brown above; under surface buffy white. The relatively short tail as compared with the tail of other shrews is a fairly good distinguishing feature.
Lyell Shrew, Sorex lyelli Merriam, is a rare species, known at present only from the general neighborhood of the peak for which it is named. Single specimens were taken by our party at Vogelsang Lake, 10,350 feet altitude, September 1, 1915, head of Lyell Canon (=: slopes of Mount Lyell) at 9800 feet, July 24, 1915, and near Williams Butte, at 6900 feet, September 20, 1915. Inhabits moist situations, near streams, in grass or under willows. Total length about 4 inches, tail 1^ inches or more, hind foot less than ^ inch (11-12 mm.). Light hair brown above, paler on under surface.
48
AMMAL LI Ft: IS Till: YOSKMITK
observation, ami usually trapping:, to clenionstrate tlu'ir presence. Shrews and moles have many features of structure and behavior in common and are classed together in an order known as Insectivora, a term which indicates their principal food. The two groups are quite distinct, however; the shrews exhibit none of the peculiar specializations for digging possessed by moles, being in general much like small mice.
|
x-Sly« |
N.p.nav |
gator |
/\ N.p. navigator | |
||
|
?iij : |
So |
obscurus :^ \^Qobscurus |
|||
|
S.mmaripbsae |
=^ |
W^ ^^ Slv.arnoenus |
|||
|
LIFE ZONES \VL' n ARCTIC ALPlNf -^ijj^. _. — |
|||||
|
^^00k=^ |
|||||
|
^ MUOSONIAN ""^ ' |
|||||
|
Sornatus L,ifjII |
jr0!^ |
r~l CANADIAN (nm TRANSITION |
|||
|
J-?gS^^'^^ |
E3 UPPtn SOmORAN |
||||
|
^•5 |
^ |
JCA CEVCL |
ED LOWtR 60N0RAN |
';!iii!i!;!i::!i:i!i»'^
Fifj. 6. Cross-section of the Sierra Nevada through the Yoseniite region showing general zonal ami altitudinal distribution of the shrews (genera Surex and Xeosorex).
The shrews live and do most of their foraging above ground, yet they keep beneath cover of varj-ing kinds such as is atforded by matted vege- tation and prostrate logs. Sometimes when foraging they invade the runways and even the burrows of other mammals — meadow mice, for instance — but none of our local species of shrews are known to make runs of their own or to put up mounds as do moles. Most kinds of shrews regularlj^ patrol the sides of streams where often there are little beaten paths close under the overhanging banks. The Dusky Shrew, and to a less degree, the Adorned Shrew, are to be found away from water, sometimes a hundred yards or more, on hill slopes covered with trees and rocks. But none is known to inhabit the dry foothill chaparral, or the sagebrush tracts.
The nose of a shrew (pi. 20) is long and slender and eciuipped with numerous sensory hairs or vibrissae. The snout witii its tHpiipment is in almost constant motion when the animal is active. The eyes, while dis- cernible, are small and do not seem to be of much use to the animal. The external ear also is small though the sense of hearing of shrews is said to be acute. The body of the shrew is cylindrical as in the mole, but the forefeet are normal in appearance like the iiind feet. The tail, thougli varying somewhat according to the species, usually occupies slightly less thfui half the total length; it is thinly haired and has a constriction or narrowing at the extreme base where it joins with the body. This latter feature is not possessed by any of the mice. The teeth of shrews are sharply pointed and serve well in holding and killing insects or tearing the flesh of other .sorts of prey.
SHBEWS 49
The shrews, though of small bodily size as individuals, constitute, by reason of their numbers and their great activity, an important biological group in the fauna of the Yosemite region. They are actually "micro- carnivores" and exhibit an even greater degree of voracity than do the larger and better known flesh-eating species such as weasels, martens, and wildcats. Shrews kept in captivity have been known to eat more than their own weight of flesh in twenty-four hours. If they do this Avhile in confinement there is no reason to suppose that their capacity would be any less (but.rather more) when they are traveling about with full freedom in the wild. It is a common experience among naturalists who are trapping to find each morning one or more of the specimens in the traps mutilated to a greater or less degree. Numerous cases of this kind came to notice Avhile we were engaged in field work in the Yosemite region. A part at least of this work may fairly be attributed to shrews, though various species of small rodents are known to eat maimed, trapped, or dead individuals of their own kind. Where only a beginning on the feast has been made, it is usually the brain of the trapped animal that is eaten. But not infre- quently the work is done so completely that only a few fragments remain — scarcely enough to identify the victim. Not only rodents but even trapped shrews suffer from attacks of this sort. And this cannibalistic tendency lias been reported by observers who have kept shews in captivity. When any of the large carnivorous mammals, such as a coyote or a fox, raids a trapped specimen, the trap and all frequently disappear; if carnivorous beetles go after such prey, they accomplish but little in a single night; but if the shrews find the victim, they are apt to make short work of it, and without disturbing the trap in any way.
Evidence of several kinds shows that shrews forage to some extent by day as well a-s during the hours of darkness. It is likely that they depend less upon sight in searching for prey than upon the senses of smell, touch, and hearing.
As an indication of the density of population among the small mammals in a favorable location, and also of the extent to which shrews (in this case the Dusky Shrew) 'police' the ground in search of food, a record of trapping near Porcupine Flat may be cited. A line of traps set in a small meadow there from June 27 to July 3, 1915, produced the following mammals: Meadow Mouse, 3; Allen Jumping Mouse, 3; Sierra Nevada Pocket Gopher, 4; Dusky Shrew, 6; total, 16, in six nights of trapping. And the traps were still catching specimens when the line was taken up. This particular meadow had a total area of about 7350 square feet— the size of a large city lot (50x147). The vegetation consisted of grasses, lupines, and a species of orchid. It is possible that so large a number of shrews did not live and forage exclusively within so limited a tract. Only
50 ANIMAL LIFE IN THE YOSEMITE
two or three may have been resident in the meadow; the others may have wandered in from adjacent territory.
The bodies of shrews have a distinctive odor, similar to that possessed by moles. This odor is currently presumed to be disagreeable to the flesh- eating birds and larger mammals, and so is of value to the shrews in saving them from attack. Examination of the stomach contents of hawks and owls elsewhere has shown that but few ' insectivores ' are taken by predatory birds. As an exception, however, a Sparrow Hawk collected by us in Yosemite Valley on October 25, 1915, had the remains of a shrew in its stomach along with parts of a meadow mouse and some insects. Perhaps each individual carnivore has to make one trial in order to learn that a shrew is an undesirable article of food.
We learned nothing with regard to the breeding places of shrews. As to season of birth and the numbers of young in a litter, only the following records can be offered: (1) Sierra Nevada Shrew, Mono Lake Post Office, May 21, 1916: 6 embryos. (2) Yosemite Shrew, Chinquapin, June 13, 1915: 4 small embryos. (3) Dusky Shrew, Mount Hoffmann, June 27, 1915: 6 large embryos; Porcupine Plat, June 29, 1915: 4 large embryos; Tuolumne Meadows, July 7, 1915 : 5 large embryos ; Merced Lake, August 24, 1915 : 2 embryos.
Navigator Shrewd Neosorex palustris navigator (Baird)
Field characters. — Size about that of House Mouse; total length 6 to 6V2 inches (150-165 mm.), tail about 3 inches (75 mm.) long. Snout pointed; fore and hind feet of about same size and structure; ear inconspicuous. Pelage short, fine in texture; hind toes fringed with short close-set hairs (pi. 20a). Coloration black or hoary black above, often with a distinct sheen; whitish on under surface.
Occurrence. — Common in Canadian Zone and parts of Hudsonian Zone, on both slopes of Sierra Nevada. Recorded from Merced Grove Big Trees (5500 feet altitude) and Chinquapin, eastward to Mono Lake Post Office and Walker Lake. Highest station, 10,350 feet altitude at Vogelsang Lake. Lives in and near swift-flowing streams. Solitary.
The Navigator Shrew is larger than any of the other shrews in the Yosemite section and is more strictly an inhabitant of axiuatic situations. We did not find even one of the animals that was more than four feet from running or standing water, and most of our specimens were taken iininc- diately at the water's edge.
In structure the Navigator Shrew exhibits marked adaptations for existence in and near streams. The feet are large (pi. 2()(;) ; the toes of the hind foot are obliquely placed and margined with close-set fringes of hairs which serve like webbing to increase the surface of the foot. Further- more, the pelage is of a rather distinctive typo, like tliat foiind in a(iuatic
SHBEWS 51
or semi-aquatic animals; it does not soak up water, but holds air within its surface. An animal swimming beneath the water presents a shining silvery appearance because of this 'envelope' of air.
This is the species which fishermen, patrolling the banks of Sierran trout streams, often see swimming in the water. The fact that this shrew is active during the daytime is thus attested.
The breeding season of this shrew occupies the summer months. In 1915, suckling females were captured at Merced Grove on June 11, in Indian Caiion on June 20, and at Porcupine Flat on June 26 (this latter individual contained 6 small embryos). A female containing 7 embryos nearly large enough to be born was taken on June 23, 1915, in East Fork of Indian Caiion. Since none of the individuals collected in the fall months was sufficiently small to be classed on superficial inspection as young-of- the-year, the adult size must be attained rapidly.
At Mono Lake Post Office two specimens of Navigator Shrew were collected, on June 30 and July 2, 1916. These were taken in grass along a stream through a poplar grove, while in the sagebrush not over 100 feet away, specimens of the Great Basin Pocket Mouse were captured. The capture of this species of shrew at such a low station on the east side of the central Sierras was unusual and also furnished a striking example of how species of animals with totally different habitat preferences may occur in close proximity because of the juxtaposition of their respective niches.
Little California Bat Myotis calif ornicus calif ornicus (Audubon and Bachman)
Field characters. — Size small, much smaller than House Mouse (slightly larger than Merriam Bat, about % size of Large Brown Bat). (See pi. 21o.) Total length about 3 inches (75-80 mm.), tail about l^/^ inches (30-39 mm.), hind foot V^ inch (6-7 mm.), spread of wings about 8I/2 inches (220 mm.). Coloration dark brown abeve, slightly paler on under surface; flight membranes, ears, lips, and muzzle brownish black. Flies with rapid fluttering of wings and marked indirection of course.
Occurrence. — Common in Upper Sonoran and Transition zones on west slope of Sierra Nevada. Recorded from Pleasant Valley eastward to Yosemite Valley. Extreme alti- tudes, 600 and 4500 feet. Forages about foliage of oaks and other trees, and around larger brush plants ; keeps usually less than 25 feet from the ground. Not colonial.
The Little California Bat is probably the most common of the bats in the Yosemite region. It is relatively abundant on the floor of Yosemite Valley and so is likely to come to the attention of summer visitors there who go walking beneath the oaks and pines at twilight. This species does its foraging close about the foliage of the trees and larger shrubs, and ordinarily it stays within a few feet of the ground. It is seemingly oblivious to human presence, so that its actions may be watched at close range.
52 ANIMAL LIFE IX THE YO SEMITE
Often this is the first species of bat to appear abroad in the evening, though it is sometimes preceded by the Merriam Pipistrelle. At El Portal on November 22, 1914, a Little California Bat was out at 5:10 p.m. At Pleasant Valley, late in May (24th to 27th) of the year following, the species was still among the first to appear, though at that season indi- viduals did not come out until much later, 7 :25 to 7 :45 p.m. The strength of the light was about the same at the two hours mentioned. The bats evidently stayed in their retreats for some 2^^ hours longer in summer than in winter.
Little California Bats are to be found in the Yosemite region throughout the year. Our records include nine of the twelve months and are so distributed as to indicate continued residence by the species, at lea.st below the 3500-foot contour. But whether the same individuals are present at all seasons or whether, like the fox sparrows, the summer population moves out and is replaced by another contingent which comes in from the north and winters here, is a point still to be determined. In Yosemite Valley bats believed to be of this species have been seen out as late as October 27. At Pleasant Valley the species was recorded abroad definitely on Decem- ber 5 (1915), and a dead individual was picked up on Smith Creek, 6 miles east of Coultcrville, on February 7, 1916.
These bats find shelter in a variety of situations. In Yosemite Valley, at 6 P.M. on August 10, 1915, a Little California Bat, after circling over and drinking at a pool near the foot of Yosemite Falls, was seen to take refuge in a crevice between boulders. On May 30, 1911, the smoke of a fire built in a rocky cavern near the foot of Illilouette Falls routed out a Little California Bat which had been hanging in a crevice overhead. A number of these bats have been found on or in the walls of old wooden buildings and a few have been discovered in crevices in pine trees. Under original conditions as well as at the present time the species was probably very adaptable in its choice of shelter.
Bats are active only at twilight and after dark. Their daytime retreats are often difficult of access or unknown and their capture is neither easy nor sure. It is therefore more difficult to gather information concerning them than concerning birds and most other mammals. For these reasons the body of accurate knowledge accumulated by naturalists is much less complete for bats than it is for many other forms of animal life, despite the fact that, in many cases, a disproportionately large amount of time has been devoted to their study. While our parties were engaged in field work in the Yosemite region one or more members would be out almost every evening attempting to shoot the bats seen coursing over hikes or ponds, or across openings in the forest; and every clue concerning the location of "roosts" was eagerly followed up. Yet our total collection of
BATS 53
bats from the Yosemite region numbers only 80 specimens, most of these being of 2 of the 9 species represented.
The wing of a bat is a thin elastic double membrane or skin which stretches between the greatly elongated 'fingers' of the forelimb and between the fifth of these and the body of the animal. The hind limbs and tail are included in this flight membrane so that the total expanse when extended is many times that of the body alone. By moving the forelimbs the bat is able to fly, and its passage through the air seems much better controlled than in the case of most birds. Most birds must dart through the air at a relatively high rate of speed in order to maintain themselves aloft, and even the swallows, which like bats feed on flying insects, must perform long sweeps through the air. The bat is able to fly fast or slowly, to turn sharply, and to check its flight abruptly, if occasion demands. It can thus control its passage through the air with greater precision. When not in flight a bat clings, head downward, to some upright surface, using for this purpose the slender, curved, and sharply pointed claws of the hind feet.
The wings of a bat are provided with numerous sensory hairs which upon being struck by air waves apprize the animal of the location of objects in its vicinity ; and this fine sense of touch, if such it may be called, is the basis of the bat's ability to course about in twilight or even in pitch darkness without striking objects as would a mammal or a bird which is dependent solely upon sight. The ears of bats are proportionately large (see pi. 21 and text figs. 7, 8), and these big external conchs probably catch sound waves made by flying insects and thus the bat becomes aware of the direction of objects of prey.
Bats spend the day in some sort of retreat, the location chosen being more or less different for each of the different species. But such retreat is never dug or modified; nor is any bat known to make a nest as do so many other nocturnal mammals. Some species such as the Free-tailed and Pallid bats are characteristically colonial ; others, such as "the Little California Bat, are usually, but not always, solitary ; while the Hoary Bat seems to be strictly solitary. Each species issues forth when the light of day has reached a certain degree of weakness — a different degree for each species — and once abroad, each hunts its prey in a rather definite niche. The pursuit of prey usually occupies only a short period at and after dusk, though additional foraging may be done just before daybreak. The daytime hours and, with most species, the middle of the night are spent in rest. Bats are therefore abroad and active less than almost any other sort of animal; this is likely made possible, in part at least, by the concentrated nature of the food upon which they subsist.
54 ANIMAL LIFE IN THE TOSEMITE
The method used in collecting bats may be illustrated by giving the circumstances under which a Little California Bat was taken at El Portal on November 20, 1914. Well before twilight the collector had taken up a station in the open where a clear view was obtainable. The first bat seen abroad on that evening was a Hoary Bat, noted at 5 :10 p.m. Up to 5 :35 four more bats, all small, the size of the Little California Bat, were seen. Twice, as these small ones crossed low places in the horizon line, and so could be seen against the sky, loads of dust-shot were fired at them. In the case of the one bat obtained, the collector fired his gun in the general direction taken by the bat after it passed the clearing; it just happened that the animal had continued its flight in a straight line. A soft thump told that the bat had been dropped. The collector lined it up with a distant object, dragged the toe of his shoe to leave a location mark, walked forward, and then at the judged distance began working over the ground in concentric circles, picking up every dark object — until his fingers encountered the soft body of the bat.
All our bats are strictly insectivorous. The food of the Little California Bat, so far as we know, consists solely of flying insects. Because of their crepuscular habits bats are able to feed upon an entirely different category of insects than are the day foraging insectivores, the swallows, swifts, fly- catchers, etc. Their forage comprises to a considerable extent beetles and moths, and since the larvae of these are often destructive forest pests, the bats are thus of material service to the trees. In truth the bats constitute one big arm of the "night patrol."
A rather unique departure in forage range was noted in the case of a Little California Bat at Pleasant Valley early in December, 1915. The house in which a member of our party was quartered there had on one side a large shed-room in which were unusually large numbers of house flies. At dusk, when the flies were buzzing about slowly and seeking warm resting places in which to spend the night, a Little California Bat would come forth from its daytime retreat and course back and forth in the room, where it found easy forage in the logy flies. All too soon, to the naturalist's way of thinking, the bat had captured enough flies for its evening meal and retired.
During the late summer and autumn months bats, as a rule, become very fat. In all probability this storage of excess nutriment is an adjust- ment to provide against winter and early spring when forage is scarce or when the weather is such that bats cannot venture out to feed. When collecting specimens during October or November, it is a rather common experience to find bats so fat that when they are shot the 'oil' begins at once to ooze out of the shot holes and, by the time the collector has retrieved his specimen, the fur of the bat will bo matted with the grease. During
BATS 55
periods of unfavorable weather some species of bats go into dormancy, a condition of reduced animation resembling that of hibernating chipmunks. But we learned nothing in this regard concerning the bats of the Yosemite.
The young of the Little California Bat are born during the early summer months. A female taken at Pleasant Valley May 21, 1915, con- tained one large embryo ; and in a group of these bats secured on July 13, 1920, there were five females each accompanied by a single youngster one- third to two-thirds grown. With this bat, young are borne but once each year, and there is only one young at a birth. These facts indicate that the existence of the species is relatively a very safe one — assuming of course that the birth rate has been adjusted to the maximum 'expectation' of casualty.
On July 13, 1920, an examination of the deserted, windowless buildings at the McLaughlin mine south of Dudley revealed the presence of eleven Little California Bats. Those mentioned in the preceding paragraph were of this lot. These bats were found by systematically ripping off the muslin-mounted wall paper. They were on the west side of the building where the wall was shaded on the outside by trees. Much previous pound- ing on the walls of other parts of the building had not disturbed them in the least. The bats were not clustered together, as is typical of colonial species, but were clinging individually to the rough boards beneath the loosened wall paper, within a circle 2 feet in diameter and only about 30 inches from the floor. There were five adult females (all in nursing condition) and five young (three females and two males). The young were clinging to the walls independent of, but close to, their mothers. Off to one side was a female without any young one. Later, when confined together in a box, two of the adults were found each with a young one attached to a nipple. The young ranged in weight from 1.6 to 3.0 grams, while the weight of the adult females averaged 4.3 grams.
High Sierra Bat. Myotis lucifugus altipetens H. W. Grinnell
Field characters. — Size medium (larger than Little California Bat, smaller than Large Brown Bat). (See pi. 21e.) Total length 3% inches (91-93 mm.) ; lower leg (tibia) well under % inch (15.3-16.4 mm.); hind foot % inch (10-11 mm.); ear % inch or over (13-15 mm.). Coloration light brown above, buflfy beneath. Distinguished in hand by relatively large hind foot, more than half length of tibia.
Occurrence. — Inhabits Canadian and Hudsonian zones on Sierra Nevada. Altitudes, 7500 to 10,350 feet. Recorded at Merced Lake and Vogelsang Lake. Flies over and about tops of forest trees, and over lakes.
Bats inhabit the entire extent of the forested regions of the Sierra Nevada but each species occurring there occupies a definite part of this general range. The territory of the present species involves two high
.j6 animal life IX THE Y OS EM IT E
zones, the Canadian and lliidsonian. Vogelsang Lake, altitude 10,350 feet, where we obtained specimens, is next to the highest recorded station of occurrence for any bat in the United States.
Small bats, presumably of the present species, were observed occasionally about our camps at Tuolumne Meadows in July; but they came out so late that it did not prove possible to shoot specimens. But at Merced and Vogelsang lakes, in late August, three individuals were secured.
At Vogelsang Lake the bats were seen close over the water, but whether they came to drink or to capture the little insects seen 'spinning' on the surface of the lake could not be learned definitely. The continued skim- ming of the bats over the water suggested that they were actually gathering insects.
On August 19 and 30, 1915, pairs of bats were seen with one individual in rapid pursuit of another. In one instance the pursued individual was shot and was found to be a female. The actual mating of bats is believed, on fairly good evidence, to occur in the fall ; but the young do not develop until spring. These pursuits may therefore have been of females by males. Between August 19 and September 6, in 1915, the High Sierra Bats made their first appearance from 6 :58 to 7 :10, on different evenings, the earliest appearance being on a quiet sultry evening.
Long-legged Bat. Myotis longicrus longicrus (True)
Field characters. — Size medium (noticeably larger than Little California Bat, smaller than Large Brown Bat) ; total length 3Vi-4 inches (90-102 mm.), lower leg (tibia) % inch (18 mm.), hind foot % inch (8 mm.), ear % inch (9-11 mm.). Coloration brown.
Occurrence. — In Transition Zone on west slope of Sierra Nevada, where recorded definitely at Dudley, 6 miles east of Coulterville. Also taken once at Walker Lake, on east slope. Forages chiefly about trees at 6 to 25 feet from grouml, occasionally higher.
The Long-legged Bat is a species of medium size which is likely to be observed flitting across the spaces between trees in the yellow pine forest of the Transition Zone. Our own definite records of the species are con- fined to two localities; but further work between altitudes of 3000 and 5000 feet on the west slope of the Sierra.s would doubtless show it to be of general occurrence there.
At Dudley, 6 miles east of Coulterville, three specimens were taken on the evenings of July 13 and 16 and August 1, 1920, respectively, as they alighted on the vertical boards beneath the gable of a barn. It was found that the bats sought this perching place repeatedly in order to devour at leisure the insect prey which they had captured while in flight. This habit of perching to eat, though it is a well-known trait of the Pallid Hat, does not .seem to have bi'cn recorded hitherto for the jji-cscnt species. Other
BATS 57
individuals of tlie Long-legged Bat were taken during the daytime from their resting places on a pine tree. At Walker Lake a bat of this species was shot on the evening of September 11, 1915, at 6 :52 p.m., from among several which were flying down the canon high over the aspens and sage- brush. These bats were probably going from their daytime resting places in the forest to some especially productive forage area farther do^vn the valley.
A female Long-legged Bat taken at Dudley on July 16, 1920, gave evidence of having recently suckled young; and on August 1, a young individual, nearly full-grown, was taken there. This young animal was clothed in hair of somewhat softer texture and more grayish color than that of the adults.
Fringed Bat. Myotis thysanodes Miller
Field characters. — Slightly larger than Little California Bat, much smaller than Large Brown Bat. Total length 31/^ inches (80-87 mm.), tail about 1% inches (37-40 mm.), hind foot % inch (8-9 mm.), ear % inch (14-16 mm.). Coloration dull yellowish brown above, paler on under surface, flight membranes, ears, and muzzle blackish. A fringe of fine hairs along edge of membrane on each side of tail toward tip is distinctive.
Occurrence. — Taken only near Dudley, 6 miles east of Coulterville ; altitude 3000 feet.
The Fringed Bat has been taken but a few times in California, and it is not yet possible to give its range, forage habits, or other characteristics with any degree of satisfaction. In the Yosemite region this bat was found only in the neighborhood of Dudley, which is near the western margin of the yellow pine belt. One immature specimen was shot at dusk at a deer lick a little north of Dudley. Another was routed out of the deserted build- ing at the McLaughlin mine where the group of Little California Bats was found. This specimen was started from its retreat by our pounding on the walls. A third individual was jarred out of a loose shake roof in an old building at the Red Cloud Mine. The first example mentioned was taken on July 21, 1920, the other tw^o on July 13 of the same year; all three were males.
Merriam Bat. Pipistrellus hesperus merriami (Dobson)
Field characters. — Smallest bat in the Yosemite region (about three-fourths size of Little California Bat). Total length 2y2-2% inches (67-72 mm.), tail 1% inches (29-30 mm.), hind foot about % inch (5 mm.), ear % inch (9 mm.), spread about 7% inches (197 mm.). Coloration warm buff above, paler beneath; flight membranes, ears, lips, and muzzle black. (See pi. 21b.)
Occurrence. — Common in Upper Sonoran and lower part of Transition zone on west slope of Sierra Nevada. Eecorded from Pleasant Valley eastward to floor of Yosemite Valley. Forages in the open, well above the smaller trees.
58 ANIMAL LIFE IS THE YOSEMITE
The Mcrriam Bat, smallest of the local bats, is a species likely to be seen by anyone ^vho visits Yosemite Valley or the neigrhboring country to the west. It appears early in the evening, being usually the first species to be seen abroad, and flies high, in the open air, well above the horizon line. Its flight is notably irregular, even for a bat, and this feature alone often serves to identify a solitary individual when comparisons of size cannot be made. The pipistrelle finds shelter in crevices among the rocks, and of such retreats it has a wide range for choice in the Yosemite.
On the evening of July 24, 1915, one of our party went bat hunting near Rocky Point, on the north side of Yosemite Valley. The first bat seen, at 7:18, was shot and proved to be a "pipistrelle." It was flying high in the open among the yellow pines and black oaks, but well away from the foliage of these trees. No other bats were seen that evening until 7 :30 when the Large Brown and the Free-tailed appeared simultaneously.
This bat is evidently resident in the foothill districts throughout the year, as a specimen was shot at EI Portal on the evening of January 1, 1915. Its continuance in the Yosemite Valley during the winter season seems doubtful; no bats, of any species, were noted there after the end of October.
At Pleasant Valley on May 22, 1915, a female Merriam Bat was obtained which contained 2 embryos.
Large Brown Bat. Eptesicus fuscus (Peale and Beauvois)
Field characters. — Size large, about 3 times that of Little California Bat, ami ouly slightly smaller than Hoary Bat. (See pi. 21d.) Total length 4^4-5 inches (110-124 mm.), tail l%-2 inches (47-52 mm.), hind foot % inch (10 mm.), ear 1,4 inch (12-13 mm.), spread of wings 13^/4 inches (337 mm.). Coloration rich brown above, pale brown beneath; flight membranes, ears, and muzzle blackish.
Occurrence. — Common in summer in Transition and Canadian zones on west slope of Sierra Nevada. Recorded from Smith Creek, 6 miles oast of Coultervillo (3000 feet), eastward to Merced Lake (7500 feet). Forages in open spaces between trees at 20 to 50 feet above ground.
The Large Brown Bat merits its name both as to size and color, as it is several times as large as the other 'brown' bats (genus Mj/otis) of the region, and its coloration is a rich brown. Since it is common in practically all parts of the Yosemite region between altitudes of 3000 and 7500 feet, it is likely to come to the attention of visitors in most of the well-known stopping places on the west slo])e of the mounlains. It has not yet been recorded on the ea.st side of the Sierras in the Yosemite section.
The Large Brown Bat does not come out until some time after the Little California and Merriam bats have b(^m to fly. In Yosemite during June of 1015 Ihis bat appeared from 7:40 to 7:50 p.m., while toward the
BATS 59
end of July the days had shortened so that Eptesicus was abroad at 7 :30. In late August, at Merced Lake, it was out at 7 -.15 p.m. ; and on October 2 that same year, in Yosemite Valley, a bat of this species was seen over Sentinel Meadow at 5 :46 p.m., when Half Dome Mas still pink-tinged with direct sunlight.
When foraging, this bat courses about in clear places in the forest or over open caiions; usually it keeps well up, anywhere from 25 to 50 feet above the ground. Each individual seems to have a definite forage route or beat. If the collector misses a shot, he is sure to have another chance at the same bat if he but holds his post until the animal swings around over its course again. The flight is relatively slow, and its course is maintained in a direct line for longer periods than is that of most other bats. These features, together with its larger size, render the Large Brown Bat an easier target for both the eye and the gun than are most other species.
The electric lights in the 'streets' of Yosemite 's tent cities serve to attract multitudes of native moths and other night-flying insects and these in turn draw the bats. One evening in July there were fully 20, mostly of the present species, to be seen about the lights in one of the camps, where they seemed to be faring exceedingly well.
Our records for this bat, based upon specimens taken, end with August 28 (1915) at Merced Lake; but bats believed to be of this species were seen until late in October. No Large Brown Bats have been observed in the region during the winter months. The species seems not to have been found anywhere in California during that season ; in all probability, like many of the birds, it retires to some more southerly locality to spend the period when flying insects are scarce or wanting in our latitudes.
HoAKY Bat. Nycteris cinerea (Peale and Beauvois)
Field characters. — Largest bat in the Yosemite region, slighly larger than either Large Brown Bat or Pallid Bat. Total length 51/2 inches (135 mm.), tail 2% inches (60 mm.), hind foot % inch (11 mm.), ear % inch (9 mm.), stretch 15y2 inches (398 mm.). Coloration 'hoary,' the hairs being brown at base and extensively tipped with white; wing membranes blackish. Tail membrane furred like back. (See pi. 21a.)
Occurrence. — Eecorded definitely twice in Yosemite region; probably rather common. Individual specimens taken at Snelling, April 15, 1916, and at Merced Lake, August 20, 1915. Inhabits wooded localities and finds daytime refuge in trees. Solitary.
The Hoary Bat, one of the most distinctive of our Californian bats, is included in the fauna of the Yosemite region on the basis of two specimens captured. On several other occasions, however, individual bats which we believed to be of this species were seen in flight.
60 ANIMAL LIFE IN THE YO SEMITE
Compared even with the Large Brown Bat the present species stands out as of very large size. As additional characters, it has long and pointed wings and a swift and irregular flight. Usually it flies low among the trees but sometimes courses up 25 to 30 feet above the ground. It appears at about the same time in the evening a.s does the Large Brown Bat. One Hoary Bat was shot at 7 :12 p.m., August 20, 1915, at Merced Lake.
The Hoary Bat is known to be a definitely migratorj' species. In winter it occupies the hills and valleys of California; in summer it goes to the higher mountains or to more northern latitudes. Its sea-sonal move- ments thus parallel those of some of our birds, the Audubon Warbler, for instance.
This bat is strictly solitary in its habits, and spends the day hanging amid the foliage of some tree. Its hea^y coat of fur, which extends out onto the upper surface of the wings and clear over the tail membrane, is an evident adaptation to the relatively low temperature of its alpine and northern habitat, and to its solitary and open manner of 'roosting.'
Pacific Pallid Bat. Antrozous pacificus Merriam
Field characters. — Size large among the local bats; slightly smaller than Hoary Bat, several times size of Little California and Merriam bats. (See text fig. 7 and pi. 21.) Total length 4-41/0 inches (103-118 mm.), tail IVo-l^ inches (36-46 mm.), hind foot Yo inch or over (12-14 mm.), car 1-1% inches (26-32 mm.), spread about 13-14 inches. Coloration pale brown above, light buff beneath; flight membranes dark brown, ears and muzzle light brown.
Occurrence. — Common in Lower Sonoran Zone, at Snelling. Lives in buildings during daytime, foraging abroad at late dusk. Hunts near the ground. Colonial.
The Pacific Pallid Bat is a rather large-bodied bat with extremely large ears. Its coloration as compared with that of the other local species is very pale. It was found at only one station, Snelling, but may possibly occur in portions of the adjacent foothill country, for it has been found in the Upper Sonoran Zone in other parts of central California. This bat appeared abroad in late May at about 7 :45 p.m. Some were seen to forage on the leeward side of a row of cottonwoods near the Merced River.
On the evening of May 27, 1915, some boys were found making an effort to rid the village church in Snelling of a colony of pallid bats which had taken possession of the wall of a gable. One of our party lent his assistance in order to obtain some specimens. A trjip of wire screen was set up in front of the opening. At 6:30 p.m. the bats had become active within the walls and could be heard squeaking. The first individual emerged at 7:30, escaped the net and flew away. Another coming out soon afterward likewise went free of the net, but then circled and alighted on the side of Iho ])uilding. No more came out unlil 7:40; then they began
BATS
61
to emerge and drop into the net at the rate of about four per minute. As darkness came on the animals came out faster and faster. The net was taken down at 8:00 o'clock after which still more were seen to emerge from the wall, circle about a bit, and then fly away. The gable of the church which harbored the bats also housed a swarm of bees and a Red- shafted Flicker,
Fig. 7. Pacific Pallid Bat; from freshly collected specimen, natural size. May 26, 1915.
Snelling,
Of the bats captured, 1 male and 19 females were saved as specimens. The male was not in breeding condition. Fifteen of the females contained 2 embryos each, 3 had 1 embryo and 1 none. Many of the embryos were of such large size as to indicate that they would have been born very soon.
Mexican Free-tailed Bat, Nyctinomus mexicanus (Saussure)
Field characters. — Size medium, more than twice size of Little California Bat, de- cidedly smaller than Large Brown Bat. (See fig. 8 and pi. 21.) Total length about 4 inches (97-103 mm.), tail about IVo inches (32-40 mm.), hind foot less than V2 inch (7-12 mm.), ear about % inch (13-14 mm.), spread of wings 11^^ to 12 inches. Color- ation dull dark brown above, paler on under surface; flight membrane, ears, and muzzle blackish. The terminal half of the tail projects behind the edge of the flight membrane (fig. 8), a character not shared with any other species of bat in the Yosemite region. Musty odor characteristic.
62
ANIMAL LIFE IN THE TOSEMITE
Occurrence. — Resident in Upper Sonoran Zone and lower part of Transition Zone on west slope of Sierra Nevada, where recorded at Coulterville, on Smith Creek (6 miles east of Coulterville), at El Portal, and in Yosemite Valley. One record for Walker Lake, east of Sierra Nevada. Forages high in open air apart from trees or other vegetation. 'Roosts' in buildings. Colonial.
The Free-tailed Bat is a bat of the open phices, and in its route of forage and manner of flight more nearl}^ resembles tlie swallows than does
any one of the other local bats. It is to be looked for over fields, or else well above the level of the tree tops or brush. A dis- tinctive feature of this species is the narrowness of its wings, a shape which is perhaps more useful to an animal flying swiftl}' in the open.
This bat is highly colonial, sometimes being found in gath- erings which include hundreds of individuals. It seeks by preference the attics of build- ings rather than natural abodes in crevices in trees or cliffs.
In time of appearance the Free-tailed Bat resembles the Large Brown Bat. Thus, the two species appeared simul- taneously at 7 :30 P.M. in Yo- semite Valley on July 24, 1920. At El Portal, January 1, 1915. a Free-tail was shot shortly after 5 :14 p.m. This latter occurrence indicates not only that this species winters in the region, but also that individuals forage abroad in midwinter when weather conditions are favorable.
The single example from the east side of the mounlains was jiicked up dead on September 12, 191;"), at Walker Lake.
At Coulterville, on June 7, 1915, two members of our party visited several buildings in the town which were reported to be inhabited by bats. The .specimens ol)tained in one of these places were all Free-tailed Bats, but whether all the buildings had been tenanted by this species could not be ascertained. The attic over the local drug store was a large affair open under the eaves .so that bats could easily gain entrance. Only four indi- viduals were seen there at the time of our visit; but on the floor of the place there was bat guano to the depth of 4 inches or more, indicating that
Fig. 8. Mexican Free-tailed Bat; from speci- men, about %o natural size. Dudley (six miles east of Coulterville), June 24, 1922.
BATS 63
a large colony had tenanted the place in previous years. Mr. W. J. McCarthy, who was a druggist there for many years, told us that he once burned some sulphur in this attic and killed "hundreds of bats." We found the village assembly hall to contain a few Free-tailed Bats crowded into a space about 2 x 4 x 36 inches beside a door casing, and others had evidently roosted along the ridge pole.
The Masonic Temple had suffered more extensively from the bats. In the low attic of this building were found only a very few individuals. But at some previous time there had been a large population, for guano lay in considerable heaps over the ceiling laths, and bat urine had stained the walls of the room beneath. We were told that "thousands" of bats had lived in this attic and that it had taken "an hour and a half for them to come out in the evening," but these multitudes were not present at the time of our visit. Guano left in the attic of such a building, sheltered from moisture, retains its characteristic odor for many years, therefore it does not give a wholly satisfactory clue as to the recency of bat occupation.
The two bats taken at Coulterville were both females and each contained one large embryo.
American Black Bear. Ursus americanus Pallas
Field characters. — Size large (adults, total length up to 60 inches, height at shoulder up to 40 inches); forefoot squarish (size, up to about 6I/2 by 4 inches), hind foot triangular in outline (total length from heel, up to about 9 inches, width to 4i/4 inches) ; all five toes and claws showing in track of each foot (pi. 22&) ; tail very short, 6 inches or less. Pelage long and heavy, in color either glossy black, or cinnamon brown of varying shades. Voice: Commonly only sniffs or snorts; when badly frightened or wounded, a loud growl or bawl.
Occurrence. — Eesident on west slope of Sierra Nevada, chiefly in Transition and Canadian zones. Recorded, or reported on good authority, from 3 miles east of Coulter- ville, from near Bagby, and from Bullion Mountain, eastward to Tuolumne River at 8000 feet, to McGee Lake, and to Tenaya Lake. Lives on forest floor or about bnish thickets, taking shelter in caves, under rock piles, or in hollow trees. Cubs run with mother through first year.
The Black Bear is the largest carnivorous animal now to be found in the Yosemite region, and, strangely enough, also the one most often seen by visitors to the Park. Indications of its presence, in the form of foot- prints, claw marks on tree trunks, and droppings, are to be seen in many places during the summer and fall months, so that persons who do not succeed in catching sight of the animals themselves are apt to find plain evidence of their presence. In former years the Grizzly Bear, a much larger and more ferocious animal than the subject of the present account, was found in the western part of the Yosemite region ; but as told in the chapter on that species, it became extinct there, at the hand of man, many years ago.
64 AMMAL LIFE IS THE YOSEMITE
Our Yosemite Black Bear exhibits two color pha-ses. That is to say, there are both 'black' and 'cinnamon' bears; but these two phases seem to hold somewhat the same relation to one another as do brunettes and blonds in the human species. A cinnamon-colored mother bear has been seen with 2 coal-black cubs, and several cases have been reported in which a female has had one black and one cinnamon-colored cub. in the same litter. The proportion of cinnamon and black bears in the Yosemite region is not known. One resident stated that it was 10 to 1 ; but our experience points exactly in the opposite direction — we hapi)eiied to see no cinnamon-colored bears at all while in the region !
The Black Bear is an animal of the Transition and Canadian zones and only rarely ranges above or below the limits of those two zones. So far as known it occurs only on the western flank of the Sierra Nevada, and in this region seldom goes above 9000 feet or below 2000 feet altitude. On the west it was probably restricted in range in former times l)y the presence of the bellicose Grizzly and it does not seem to have taken much advantage of the disappearance of its larger congenor to increase its range, while in the higher zones conditions are evidently not suitable for its existence.
The density of the bear population of the Yosemite National Park varies widely from place to place. It has been estimated that at times there have been 15 or 20 bears living in Yosemite Valley, the greater per- centage of these being about the lower part of the Valley. On the trail between Aspen Valley and Gentry's, a distance of 8 or 9 miles, the junior author saw tracks of 5 or 6 different Black Bears in one day, October 19, 1915. But in other likely-looking places the animals are much scarcer, or absent altogether. Perhaps there are, at the present time, somewhere in the neighborhood of 125 bears in the 1124 square miles of territory included within the Park, or about one individual for every 9 square miles of territory. The mecca of the bears in the Yosemite region is the north- central part of the Park, in Tiltill and Pleasant valleys, Kerrick Canon, and on the slopes of Rancheria Mountain. Bears are said to be abundant in each of these localities. In Pleasant Valley (north of the Tuolumne River) the brushy slopes are said to be traversed in many directions by their deeply worn trails.
Most carnivorous animals are abroad and active throughout the year, and if, in winter, the presence of heavy snow either directly or indirectly restricts or cuts off their food supply they descend to lower altitudes. Such is the case with the Mountain Coyote and the Mounlalu Lion. But the Black Bear, depending as it does on plant life for so mucli of its food, is a striking exception to this general rule and meets the situation in an entirely different way. It hibernates, after the manner of some of the rodents. With the
BEARS 65
arrival of the first heavy storm of the winter (usually in December or January) it seeks a warm and sheltered cave among the rocks or some other similar situation and there sleeps during the time that heavy snow covers the ground outside. It remains in hibernation until the middle or end of April, when the bulk of the snow at middle altitudes has melted. In 1920 the first bear tracks noted in the lower part of Yosemite Valley were seen on March 18. Those individuals which live below the limit of heavy snow (about 3500 feet in this latitude) are prone to come out and forage actively abroad from time to time throughout the winter. Some residents of the region have suggested to us that the bears living in the higher mountains perform a limited altitudinal migration, but we have no definite informa- tion on this point.
The dens used by the bears in the Yosemite region are chiefly such as are found in the heaps of talus and slide rock which abound in various parts of the Park. The bears which feed at the garbage pits in the Yosemite Valley are thought to have their dens in the rock slides under Cathedral Spires, for in this vicinity a trail leads from the pits toward the wall of the Valley.
When the Black Bears go into hibernation in the early winter they are very fat, but most of this excess fat is used up during the long winter sleep. When they first emerge in the spring they are not very active and little is to be seen of them for some time. Soon, however, they begin to eat again, sparingly at first, and then more greedily, until in summer and fall they amply justify the oft-made remark, ' ' hungry as a bear. ' ' As the summer wanes their search for food leads them farther and farther afield, their tracks and sign become more and more in evidence, and they themselves are more frequently seen by visitors. During the autumn they must eat not only to sustain their bodies from day to day, but enough in addition to provide another supply of fat to carry them through the following winter. This fat is especially important in the case of the females, as their cubs are born in midwinter and the only source of nourishment for the young until they emerge in the spring is the milk elaborated in the bodies of the mothers from this reserve of fat.
Under original conditions of life the Black Bear is active in the daytime as well as at night, but most of the depredations which it commits in the vicinitj^ of camps and buildings are done under the cover of darkness. The Black Bear is an adept at climbing, from the day that it first emerges from the den, a young cub in the care of its mother, on throughout its entire life. When frightened it often seeks safety by ascending the nearest tree strong enough to support it. When trailed by dogs it finally evades them in this manner.
(iC AMMAL LIFE I\ THE YOSEMITE
The tracks of a bear are not likely to be mistaken for those of any other animal. The toes and claws, of which there are five on each foot, all leave distinct impressions in the soft earth of roads and trails, while the square pad of the forefoot and the triangiilar-shaped heel pad of the hind foot are both of distinctive character (pi. 22h). The track of the rear foot resembles in appearance the print of a human foot. We have measured hind-foot tracks which were 9 inches long, but the average length is con- siderably less.
Bears are adaptable creatures and profit by the presence of man in several ways. They make much use of man-made trails, especially when going up or down hill, and when doing so follow each turn and zig-zag with remarkable fidelity. Their o^^^l trails are as distinctive in char- acter as are their footprints. Through tracts of dense brush the openings left are low — so low in fact that a man in traversing one of them must stoop or crawl on his hands and knees. Then, too, each bear steps in exactly the same place as the one which preceded him, literally "walkinj]: in the footsteps of his predecessors," and if a bear comes into a trail of this sort at some point along its course he adapts his tread to that of the main trail. These traits are well shown in a trail through light snow, where the tread of the animals crushes down and melts the snow where they step, yet leaves the snow between the footprints undisturbed (jil. 22a).
Black Bears usually have 2 cubs at a birth, but on June 19, 1910, the junior author saw a black female with 3 black cubs near Camp Curry on the floor of Yosemite Valley. In the account of the Grizzly killed by R. S. Wellman there is mention of 3 Black Bear cubs with their dam, these being actively abroad a.s late in the season a-s October 17. Sometimes a litter consists of but a single cub. The earliest report of young out of the den is that by Mr. 0. R. Prien who, during the week of April 29, 1916, saw a female with 2 black cubs less than 18 inches long. The cubs of one litter travel with the mother until she dens up for the following winter. Mr. Gabriel SouveleAvsky saw tracks of an old bear and two "good-sized" cubs near Mirror Lake, on December 14, 1914.
As regards food the Black Bear will eat anything and everything it can lay its paws on. It is an omnivorous feeder in every sense of that word, departing widely from the customs of most carnivorous animals in this respect. In its natural environment our Yosemite bear eats various kinds of seeds, fruits, and berries, including those of the coffee beriy {Rhamnus calif ornicus), green manzanita {Arctostaphylos patida), wild cherry {Prunua drniissa), and ])oison oak (Wiun divcrsiloha). Grasses, liliaceous plants, and seed heads of varioiis annuals are consumed. Carpenter ants and other insects are taken in considerable mmilxTs. In the vieinily of human habitations it finds a wide elioiee of far(>. It visits isolated or
BEAB8 67
unguarded camps and purloins hams, bacon, canned goods and fruits, raids garbage cans, and digs up heaps of tin cans and other kitchen refuse buried by campers. A considerable number of the bears living in Yosemite Valley regularly forage at the garbage pits and incinerators in the vicinity of Cathedral Spires, as many as 10 and even 15 having been seen there by attendants, usually at late dusk. Tin cans are nosed over and thoroughly cleaned of any remaining particles of their original contents, and melon rinds and other vegetable materials are readily devoured. Peach, plum, and olive pits, watermelon, muskmelon, and apple seeds, lemon rinds, eggshells, bones of chickens, mammal hair, and bones from various cuts of meat are among the objects we found to have been devoured by these bears. Even papers which have been wrapped around butter and cured meats are eaten for the grease and salt which they have absorbed. At the storehouse of the construction camp in Hetch Hetchy Valley, in the winter of 1915-16, bears ripped 2-by-12-inch planks off the window openings, clambered in, and made way with hams, bacon, and canned goods, even while lights were burning in the house and persons were present in other portions of the building.
As regards the relation of Black Bears to stock, Mr. George Smith of Jamestown, Tuolumne County, has told us that in the seventies it was necessary to 'thin out' the bear population before sheep could be run with safety in the mountains. At that time almost every meadow had its bear trap or pen, a small log house of stout construction with a heavy door so arranged that when a bear entered and seized the bait the door would fall and the animal would be imprisoned. Some of these traps may still be seen on meadows in the northern part of the Park. Horses readily take fright at the sight of a bear, although we know of no case in which a bear has actually attacked a horse. In Hetch Hetchy Valley Mr. C. C. Bull has told us of bears visiting hog pens and feeding in the troughs alongside of the rightful partakers without molesting or disturbing the latter. Mr. John L. McLean has told us that bears come down around his ranch on Smith Creek (6 miles east of Coulterville) to feed on acorns, but that they have never molested either poultry or stock. However, he knew of one occasion when some pigs were taken by Black Bears on Bullion Mountain.
Finally in regard to persons: We know of but two instances in which a Black Bear has even attempted to molest any human being in the Park. One case, of a mother bear resenting disturbance of her young, is recounted in the chapter on the Grizzly Bear. The second instance is as follows. Mr. George Smith states that while cruising timber in the Tuolumne basin a number of years ago he was chased down-hill by a she-bear. He distracted the attention of the animal by picking up stones and pieces
68 ANIMAL LIFE IN THE YO SEMITE
of wood and throwing them to one side or another as he ran. Finally he jumped upon and ran along a fallen tree trunk and dropped into a willow thicket at the base of the log. The bear, evidently losing the trail, thereupon gave up the chase. Mr. Gabriel Souvelewsky relates that while traveling along the south wall of the Tuolumne Cafion late one afternoon he came to a rock ledge occupied by two cinnamon bears. One of these growled and made threatening advances so that Mr. Souvelewsky thought it best not to continue farther in their direction. But he wa.s not actually pursued. The female mentioned above as being seen by the junior author near Camp Curry in June, 1910, even though accompanied by her cubs, was not unduly resentful of human intrusion. Several persons were taking pictures of her while she had her cubs in sight, and later, when she had hidden them, she came down and fed at a garbage heap while some forty people looked on and snapped pictures at as short a distance as twenty feet.
Grizzly Bear. Ursus henshawi Merriam
The history of the Grizzly Bear in the Yosemite region and indeed throughout California is evidently a closed chapter in the book of nature. In the "days of '49" numbers of the big fellows roamed over the hills and valleys of California, and the Yosemite region doubtless had its full quota of them. But the presence of the Grizzlies was incompatible with the interests of the white man, and so they were killed off rapidly, until now it seems likely that they are entirely gone. So sudden was their extermination that no complete specimens were secured to be preserved in our museums. And reliable accounts, published or in manuscript, of the California grizzlies are meager at best.
The word Yosemite^ is derived from a word in the tribal dialect of the southern Miwok Indians who inhabited the Valley when it was discovered by white men. This word, Uzumati, or Uzhumati, means grizzly bear, a full-grown animal rather than a cub. The use of this name in as.sociation with the Valley might be taken as an indication that Grizzly Bears orig- inally inhabited the Yosemite Valley. But we have no precise evidence to show that such was the case. Early visitors to the Yosemite often mention "grizzlies" and "bears" in their narratives, but with an am- biguity that leaves the reader uncertain as to whether a veritable Grizzly was encountered anywhere in the Valley proper.
The names Bear Valley, Bear Creek, Big Grizzly Flat, and Little Grizzly attest the former wide occurrence of Grizzly Bears in the foothill district of the region.
8 For the circumstances Burrounding the choice of the nanio consult L. H. Bunnell, Discovery of the Ynxrmite; for diFCUFsion of tho nionning of the word see paper by A. L. Kroebcr, (^.-iliforiiia Place Names of Indian Orijrin (Univ. Calif. Publ. Am. Arch. Ethn., vol. 12 [1916], p. 68).
BEAES 69
The Grizzly Bears as a group (including several species and races) are quite distinct from the Black Bears. The size of adults was generally much larger, though the species which occurred in the Yosemite region was one of the smaller of the grizzlies. No weights or detailed measurements of locally captured grizzles are preserved. The "nose to tail" measurement of "nearly 10 feet" given by its captor for the Wellman specimen referred to below, applied to a skin as pegged out fresh. It is well known that considerable stretching results from such procedure, and that when the skin is relaxed and tanned it shrinks somew^hat. The length of the Wellman grizzly skin is now 71/2 feet and its width at the middle is 5 feet. Judging from the dimensions of bears before skinning, in known cases, as compared with those of the tanned skins measured subsequently, the Wellman bear in the flesh probably measured between 6I/2 and 7 feet in length, tip of nose to tip of tail. The Washburn skin mentioned later measures 6 feet 7 inches in length, somewhat smaller ; and the living animal was therefore probably close to 6 feet long.
The foreclaws of the Grizzly are much less sharply curved and some- what longer than those of the Black Bear; this is an absolutely distinctive character. The longest claws on the AVellman skin are 3 inches (measuring the chord of the claw from tip to upper base), while the middle fore- claw of a large California-taken Black Bear is only 2 inches in the same dimension. The track of an old Grizzly, either front or hind foot, was much larger than that of a Black Bear. Wellman 's figures, 10 by 13 inches, and McLean's, 9 by 17 inches (even allowing for considerable sliding of the foot, especially in the latter case) are 50 per cent larger in each dimen- sion than the track of a good-sized Black Bear. These measurements of course refer to the hind foot, which is decidedly longer than the forefoot. The latter (if the 'wrist' does not touch) leaves an imprint that is more nearly square in outline. In coloration the Grizzly was dark brown, and some individuals had grayish or whitish ends to the longer guard-hairs on the back, which gave rise to the name ' ' silver-tip. ' '
The Grizzly differed from the Black Bear in habits as well as in struc- ture. It was, particularly in the case of the Henshaw Grizzly, a frequenter of chaparral (and hence essentially an inhabitant of the foothill districts), and it never (or rarely) climbed trees. Its food, as with the Black Bear, was quite varied, including berries, fruits, and insects, as well as flesh; but the Grizzly worked much more havoc among large game, and in later years, stock, than does its smaller relative.
During our work in the western part of the Yosemite section we questioned numerous old residents concerning the former occurrence of Grizzly Bears, but rarely obtained definite information. Mr. J. B. Varain, of Pleasant Valley (= Varain), told us that there were no Grizzlies there
70 ANIMAL LIFE IN THE YOSEMITE
when he arrived in 1867, but that they were then still to be found in the territory to the east. The various gold rushes to Tioga and Mammoth, together with the running of sheep and other stock in the region, served to clear the Yosemite country of its Grizzlies at a relatively early date. The occurrence of the one taken in 1887, by Wellman, was by that year considered an unusual event.
We were unable to get track of even a fragment of a specimen of the Grizzly in the narrow section which we worked across the Sierras; but since our field work was completed, there have come to light two skins of Grizzlies killed elsewhere within the present boundaries of Yosemite National Park. Both of these skins are now in the Museum of Vertebrate Zoology of the University of California. One of these bears (obtained from IMrs. John S. Washburn) is the last known to have been killed in the region. It was shot "about 1895" at Crescent Lake, which lies some ten miles air-line east of Wawona at an altitude of 8500 feet.
It is possible that a few individuals persisted in the same region until a considerably later date. This surmise is strengthened by the following account. Mr. John L. McLean and his son Donald have told us that during the fall and winter months from 1908 until 1911 a very large bear lived on Bullion Mountain. The tracks, which were examined on two or more occasions in two successive years, "were 9 by 17 inches (or a little more) by actual measurement." The animal had long claws, as shown by the tracks. The bear had five separate trails leading up the side of the moun- tain from the heavj' chaparral (composed of Adenostoma and scrub or "vine" oak) on the lower slopes, to the black and blue oaks on the top. The dung indicated that the bear was living principally upon acorns. There were wild hogs on the mountain and these may have been an attrac- tion to the big bear. The smaller (Black) bears seemingly had little or nothing to do with the big fellow, avoiding his trails and staying off in another canon. A trap was once set for the big bear, and caught him ; but he pulled loose "at one jump." Finally a party of men with dogs got after the big bear and it "left the country," without being injured, and was not seen again. Small bears are still present in the region.
The circumstances surrounding the killing of the "Wellman bear" have been set down at considerable length in a letter written by one of the principals, Mr. Robert S. Wellman, under date of April 20, 1918. This letter is now on file at the Museum of Vertebrate Zoology, and from it we take the following.
Mr. Wellman 's headquarters were, at that time, at Buck Caniii, sonit> 16 miles east of Wawona, near the South Fork of the Merced River. On the evening of October 17, 1887, at the head of a small valley about a mile away from the camp, he discovered the carcass of a cow on which bears
BEARS 71
had already commenced to feed. A search of the vicinity disclosed the presence of a female Black Bear and three cubs.
The next morning Mr. Wellman visited the place again and found that during the night a larger bear had come and dragged the carcass several yards from where it first lay. Being certain that this new arrival was a veritable Grizzly he rode over to the camp of his friend Jim Duncan,* now long deceased, and got him to come over to help in the hunt. The two men built a scaffold, or platform, 10 feet above the ground and some 60 feet from the dead cow. And on this platform watch was kept for the succeeding three nights. One or more black bears and a coyote came to feed, but it was not until the third night that the big bear put in its appearance again. When it did, it happened that three small bears were at the carcass; but these quickly quit the vicinity when the large bear appeared. Finally, the Grizzly caught sight of the scaffold, and made toward it. The two men fired simultaneously and the bear fell to earth with a series of 'bawls,' evidently wounded. The men did not come down until daylight, when the animal was found in some bushes and killed by a shot behind the ear.
The skin of this bear was sold by Mr. Wellman to the artist, Thomas Hill, and, through the latter 's son-in-law, was procured in 1918 for the University of California.
Mountain Coyote. Canis latrans lestes Merriam^
Field characters. — General appearance that of a large collie dog (pi. 39a) ; head and body about 30 to 33 inches long, tail with hairs 12 to 15 inches; ears pointed, about 414 inches (114 mm.) high, habitually carried erect. General coloration gray, or grayish
4 This is in all probability the same Duncan mentioned by John Muir in the chapter on "The Animals of the Yosemite" in his book, Our National Parks (see Bibliography, p. 667). Muir relates that Duncan, who had quite a reputation locally as a bear hunter, had a cabin on the shore of Crescent