GIFT OF UNIVERSITY OF CALIFORNIA PUBLICATIONS BULLETIN OF THE DEPARTM ENT. OF GEOLOGY Vol. 7, No. 5, pp. 61-115 Issued October 12, 1912 CONTRIBUTIONS TO AVIAN PALAEON- TOLOGY FROM THE PACIFIC COAST OF NORTH AMERICA BY LOYE HOLMES MILLER UNIVERSITY OF CALIFORNIA PRESS BERKELEY UNIVERSITY OF CALIFORNIA PUBLICATIONS NOTE. The University of California Publications are offered in exchange for the publi- cations of learned societies and institutions, universities and libraries. Complete lists of all the publications of the University will be sent upon request. For sample copies, lists of publications and other information, address the Manager of the University Press, Berkeley, California, U. S. A. All matter sent in exchange should be addressed to The Exchange Department, University Library, Berkeley, California, U. S. A. OTTO HARRASSOWITZ B. FRIEDLAENDER & SOHN LEIPZIG BERLIN Agent for the series in American Arch- Agent for the series in American Arch- aeology and Ethnology, Classical Philology, aeology and Ethnology, Botany, Geology, Education, Modern Philology, Philosophy, Mathematics, Pathology, Physiology, Psychology. Zoology, and Memoirs. Geology. ANDREW C. LAWSON and JOHN C. MERRIAM, Editors. Price per volume, $3.50. Volumes 1 (pp. 435), II (pp. 450), III (pp. 475), IV (pp. 462), V (pp. 448), completed. Volume VI (in progress). Cited as Univ. Calif. Publ. Bull. Dept. Geol. Vol. 1, 1893-1896, 435 pp., with 18 plates, price $3.50. A list of the titles in this volume will be sent on request. VOLUME 2. 1. The Geology of Point Sal, by Harold W. Fairbanks ," 65c 2. On Some Pliocene Ostracoda from near Berkeley, by Frederick Chapman lOc 3. Note on Two Tertiary Faunas from the Rocks of the Southern Coast of Vancouver Island, by J. C. Merriam lOc 4. The Distribution of the Neocene Sea-urchins of Middle California, and Its Bearing on the Classification of the Neocene Formations, by John C. Merriam lOc 5. The Geology of Point Reyes Peninsula, by F. M. Anderson - 25c 6. Some Aspects of Erosion in Relation to the Theory of the Peneplain, by W. S. Tangier Smith 20c 7. A Topographic Study of the Islands of Southern California, by W. S. Tangier Smith 40c 8. The Geology of the Central Portion of the Isthmus of Panama, by Oscar H. Hershey 30c 9. A Contribution to the Geology of the John Day Basin, by John C. Merriam 35c 10. Mineralogical Notes, by Arthur S. Eakle lOc 11. Contributions to the Mineralogy of California, by Walter C. Blasdale 15c 1 2. The Berkeley Hills. A Detail of Coast Range Geology, by Andrew C. Lawson and Charles Palache 80c VOLUME 3. 1. The Quaternary of Southern California, by Oscar H. Hershey 20c 2. Colemanite from Southern California, by Arthur S. Eakle : 15c 3. The Eparchaean Interval. A Criticism pf.the use of the term Algonkian. by Andrew C. Lawson ./...".. -V .*.**. ..*. i ?\....Jl lOc 4. Triassic Ichthyopterygia ifom aliforma? cl Nevada, by John C. Merriam 50c 6. The Igneous Rocks. n^aj- Pa^jarQ, Jjy .John .A.* -Reid 15c 7. Minerals from Leok Ke^gl^3,;A4arra5da:Gir v California, by Waldemar T. Schaller 15c 3. Plumasite, an Oligo'cla'se-Cofuridum " < E?<5c*k", * n'ear Spanish Peak, California, by Andrew C. Lawson .'.. lOc 9. Palacheite, by Arthur S. Eakle : ]0c 10. Two New Species of Fossil Turtles from Oregon, by O. P. Hay. 11. A New Tortoise from the Auriferous Gravels of California, by W. J. Sinclair. Nos. 10 and 11 in one cover lOc 12. New Ichthyosauria from .the Upper Triassic of California, by John C. Merriam 20c 13. Spodumene from San Diego 'County, California, by Waldemar T. Schaller lOc 14. The Pliocene and Quaternary Canidae of the Great Valley of California, by John C. Merriam 15c T .5. The Geomorphogeny of the Upper Kern Basin, by Andrew C. Lawson 65c 16. A Note on the Fauna of the Lower Miocene in California, by John C. Merriam 5c 17. The Orbicular Gabbro at Dehesa, San Diego County, California, by Andrew C. Lawson lOc 18. A New Cestraciont Spine from the Lower Triassic of Idaho, by Herbert M. Evans lOc 19. A Fossil Egg from Arizona, by Wm. Conger Morgan and Marion Clover Tallmon lOc 20. Euceratherium. a New Ungulate from the Quaternary Caves of California, by William J. Sinclair and E. L. Furlong , lOc 21. A New Marine Reptile from the Triassie of California, by John C. Merriam 5c 22. The River Terraces of the Orleans Basin, California, by Oscar H. Hershey 35c UNIVERSITY OF CALIFORNIA PUBLICATIONS BULLETIN OF THE DEPARTMENT OF GEOLOGY Vol. 7, No. 5, pp. 61-115 Issued October 12, 1912 CONTRIBUTIONS TO AVIAN PALAEONTOL- OGY FROM THE PACIFIC COAST OF NORTH AMERICA BY LOYE HOLMES MILLEE CONTENTS PAGE Introduction 62 Acknowledgments 62 Significance of Osteological Characters in Ornithology 63 Review of the Literature 64 Material available 66 Oligocene Fauna 66 Miocene Fauna 67 Pleistocene Fauna 68 Potter Creek Cave ! :::.. 68 Samwel Cave 71 Hawver Cave - - 73 Eancho La Brea 75 Fossil Lake 78 Rodeo Pleistocene 82 Present Physiographic and Geographic Relations of the West-American Regions in which Fossil Avian Remains are known 82 Relation of Pleistocene Faunas to those of the Present Day 84 Distribution of the Cathartidae 85 Distribution of the Falconidae 92 Anomalies in Distribution 96 Possible Influences Conditioning Present Distribution of Certain Groups 102 Bird Remains as Indicators of Climatic Conditions 103 Time Relations as Suggested by a Study of Bird Remains 105 Causes of Extinction of Birds 108 Tabular Arrangement of West-American Pleistocene Avifaunas 112 Bibliography of Pacific Coast Fossil Avifaunas 115 244558 .' *_-'. * c * S * T * * * *.* '< / V* . * j *** 62 University of California Publications in Geology [VOL. 7 INTRODUCTION When the vertebrate palaeontologist turns his attention to the group Aves as represented in North America, especially if he be confronted with the problems represented by a considerable mass of unassorted material, he cannot but feel that he pushes out into almost uncharted waters, a wide sea where the few islands recorded by previous explorers islands too often shrouded in mist may perhaps never appear upon his horizon. The scarcity of previous record, the wide separation in place of the bird-bearing deposits, coupled with the inadequacy of descrip- tions and the poverty of museums in collections of Recent avian osteology rail these are factors which conspire to give the student entering upon such an undertaking the feeling that he stands or falls unto himself. In full cognizance of these conditions the present paper is undertaken. Its dual purpose is the recording of certain facts but recently made known in this interesting field, and the correlating, insofar as this is possible, of the results thus far attained. ACKNOWLEDGMENTS Study of the University of California collections was taken up at the invitation of Professor John C. Merriam, head of the Department of Palaeontology of that institution, and to his unstinted aid, encouragement, and advice much of what value this study may possess is here freely ascribed. Grateful acknowl- edgement is also made to Messrs. Joseph Grinnell and H. S. Swarth of the California Museum of Vertebrate Zoology for information cheerfully furnished on many Recent species and for the loan of osteological material. Specimens of great interest and value were loaned or donated by Dr. F. A. Lucas, Dr. A. Smith- Woodward, Dr. F. C. Clark, Dr. C. O. Esterly, Mr. E. J. Fischer, and Mr. J. Z. Gilbert. The very generous attitude taken by Madam Ida Hancock-Ross and the associated owners of Rancho La Brea in issuing permits to excavate the asphalt de- posits made possible the assembling of much valuable material essential to the work. Through the personal efforts of Dr. J. C. Hawver, of Auburn, California, as well as by the very cordial 1912] Miller: Pacific Coast Avian Palaeontology 63 assistance extended by him to the author, our knowledge of the Hawver Cave deposits has been greatly advanced. To each of these persons the author's sincere thanks are extended. SIGNIFICANCE OF OSTEOLOGICAL CHARACTERS IN ORNITHOLOGY In a zoological group of such narrow delineation and of such great homogeneity as the class Aves, where separation into the various systematic divisions is based upon relatively small varia- tions and where these variations affect structures not preserved for study, a considerable degree of care must be exercised when interpreting discoveries of the palaeontologist in terms of modern systematic zoology. The difference noticeable to. a worker in the former field should in many cases be multiplied by a very large factor upon their transposal to the latter. Degrees of diver- gence which to the palaeontologist seem of no more than specific rank might, by the worker in systematic ornithology, having also various intricate details of color-pattern or feather struc- ture at his disposal, be found correlated with differences of more than generic importance. The distinction upon osteological characters of many well-defined species of Recent birds is a matter requiring complete skeletons of individuals of known sex ; even then conclusions are often in question. It is here con- ceded as possible under these conditions, and considering the fact that most of the fossil specimens are not capable of articula- tion, that many of the fossil specimens ascribed to living species might, if all characters were determinable, be separated as dis- tinct forms. It must be remembered also that within certain groups the osteological differences between species is greater than in others. The feather of the bird is an epidermal structure which reflects with sensitiveness the activities of the animal and is plastic as a specific character under the influences of environ- mental changes. It is a proper basis of specific distinction, yet it is almost never preserved in the fossil state. The tooth of the mammal, likewise an epidermal structure and highly repre- sentative of the animal's activities, is a character used in com- mon by the palaeontologist and the modern systematist. Zoology and palaeontology are then much more nearly upon the same 64 University of California Publications in Geology [VOL. 7 basis in the determination of mammals than is the case with birds. Recognizing this principle, the author of this paper has proceeded with perhaps more than necessary caution in the an- nouncement of new species, preferring to err on the part of conservatism rather than to confuse the literature of the subject by making assertions which must later be modified ; and there are in the collections studied many specimens regarding which fur- ther knowledge is considered necessary before problems upon which they may throw light can be attacked in more than a speculative way. REVIEW OF THE LITERATURE Since the epoch-making discoveries by Marsh which added so materially to our conception of the ancestry of birds, con- tributions to knowledge in the field of avian palaeontology have been few as compared with the rapid enlargement of our under- standing of the other vertebrate groups. Bird remains on the Pacific Coast are mainly from Pleistocene strata; thus there is eliminated the probability of shedding much new light upon the ancestry of certain groups in which our interest is so acutely focused, for example the Stereornithes. Discoveries recently made have contributed to science chiefly in two ways, first in giving us an appreciation of the relative antiquity of the main groups into which birds are divided; and, second, in adding to our knowledge of the geographical distribution of these groups. The consideration of geographical distribution is but begun when we record the range of the Recent species. Determination of the factors which have led to such distribution, if we aspire to something better than mere speculation, must look to the record of previous conditions as brought to light through palaeontol- ogical inquiry. The fossil-bearing rocks of the Pacific Coast of North America, while rich in the remains of mammals and reptiles, have until recently yielded but little information concerning the avian group. In 1878, Cope 1 described three new species of birds from the Equus Beds of Oregon. All three species belong to genera i Cope, E. D., Bull. U. S. G. S., Terr., iv, No. 2, May 3, 1878. 1912 J Miller: Pacific Coast Avian Palaeontology 65 still inhabiting the region; thus their importance is limited to the evidence they furnish of the division of a genus into several coordinate species. In 1892, Shufeldt 2 published the results of an extended study of the Cope and the Condon collections of birds from this same region. In this very thorough discussion there are fifty species enumerated, fourteen of which are described as new. The entire number, with the exception of the gallinaceous Paleotetrix gilli, are assigned to existing genera. Phoenicopterus is the only existing genus recorded which is foreign to the region at present. In 1894, Cope 3 described a single species, Cyphornis magnus, from a formation in Vancouver, British Columbia, which he placed with some reservation in the Eocene, but which was later considered by others to be Oligocene. The species is considered as pelecanid in its affinities but generically distinct from any form now living. Lucas, in 1901, 4 described a new genus and species of diver, Mancalla calif orniensis, from a formation at Los Angeles, Cali- fornia. From the associated invertebrate fauna, this species is considered by Dall to be of upper Miocene or lower Pliocene age. As a result of the preliminary study put upon the University of California collections by the present writer, there have ap- peared a series of short papers dealing with a number of species from Fossil Lake, Oregon, and from the~~caverns and the asphalt beds of California. While these papers record one unique form, Teratornis, of unusual interest, the main value of the contribu- tions, like that of Shufeldt 's, lies in the light shed upon the former distribution of families of birds still living. 5 2 Shufeldt, E. W., Journ. Acad. Nat. Sci. Phila., Ser. 2, No. 9, p. 389, 1892. s Cope, E. D., Journ. Acad. Nat. Sci. Phila., Ser. 2, No. 9, p. 449, 1894. * Lucas, F. A., Proc., U. S. Nat. Mus., vol. 24, p. 133, 1901. s Miller, L. H., Univ. Calif. Publ., Bull. Dept. Geol., vols. 5-6 passim, 1909-11. 66 University of California Publications in Geology [VOL. 7 MATERIAL AVAILABLE The material upon which studies of the west coast fossil birds have been based has been collected from nine different horizons, summarized as follows : OLIGOCENE Vancouver, B.C. One species (a single specimen). MIOCENE Virgin Valley Beds, Virgin Valley, Nevada. One species. Los Angeles, California. One species (a single specimen). PLEISTOCENE Potter Creek Cave, California. Sixteen species. Samwel Cave, California. Nineteen species. Hawver Cave, California. Twelve species. Eodeo Pleistocene, California. One species (a single specimen). Eancho La Brca, California. Forty-nine species. Fossil Lake, Oregon. Fifty-three species. The avian collections assembled at the University of Cali- fornia represent seven of these localities. One of the seven is identical with that studied by Cope and Shufeldt, namely, the Fossil Lake region of Oregon. The remaining six collections, so far as known to the writer, have not been studied previous to the assumption of the task here in part recorded. Three or four hundred specimens represent the bird remains from the caves, and three or four thousand have been taken from the asphalt at Rancho La Brea. So far as can be learned, the Oligocene horizon yielding Cyphornis to Cope, and the Miocene, from which Lucas described Mancalla, have yielded no other avian fossils. OLIGOCENE FAUNA Cyphornis magnus Cope is the only species known to the coast from strata of possibly so great age. The form was de- scribed by Cope 6 from a single specimen, the proximal end of a tarsometatarsus, the property of the Geological Survey of Canada. The osteological characters displayed by the speci- men are such as to have led Cope to assign the species with some reserve to the family Pelecanidae. Interest centers to some extent in a combination of the two characters, e Cope, E. D., Journ. Acad. Nat. Sci., Phila., Ser. 2, No. 9, p. 449. ]894. 1912] Miller: Pacific Coast Avian Palaeontology 67 large size and high degree of pneumaticity. The latter character was considered by the author of the species as indicating the bird's ability to fly. If such conclusion be true, the species, since the tarsometatarsus equaled in size that of the rhea, must be considered as the largest known flying bird. It may not be out of place here to consider the propriety of Cope's position regarding the relation of pneumaticity to the power of flight. Let it be conceded that Cyphornis belonged to the Pelecanidae, birds of large size which are possessed of a high degree of pneumaticity. We may then ask if the char- acter pneumaticity necessarily became vestigial or disappeared with the loss of ability to fly resulting from increased size. The development of such a character as gigantism might be a matter of comparatively short time, while the persistence of the char- acter pneumaticity might be very tenaceous. An instructive case in point is that of Geococcyx, a cuckoo of terrestrial habit whose powers of flight have been almost entirely sacrificed. The pec- toral arch in this bird is an absurdly weak structure, while there is an accompanying accentuated development of the pos- terior limb region. Despite this inversion of the appendicular parts, the skeleton remains highly pneumatic. It seems well within the range of possibility that Cyphornis should have gained its large size by a rapid specialization a tendency run riot under certain conditions not adverse to it and yet this specialization cost the bird its power of flight without blotting out the character of pneumaticity. MIOCENE FAUNA Mancalla calif or niensis Lucas, from the upper Miocene of Los Angeles, California, is described by Lucas 7 as being much like the Recent species of murre (Uria troille) of that region, but more highly specialized in that it was probably without the power of flight. The single specimen known consists of the major part of the left humerus of a bird about the size of the recently extinct great auk (Plaurus impennis). Interest in this discov- ery lies largely in the strong similarity of the bird to Recent 7 Lucas, F A., Proc. U. S. Nat. Mus., vol. 24, p. 133, 1901. 68 University of California Publications in Geology L V L - 7 forms, in its flightless character suggesting to the author of the species an insular breeding-ground free from enemies, and finally in the fact that the accompanying molluscan fauna in- dicates a climate cooler than that which characterizes the region at present. It is regretable that a larger number of species was not discovered in the same horizon. PLEISTOCENE FAUNA Potter Creek Cave. Potter Creek Cave 8 takes its feiame from its location on Potter Creek, about one mile east of Baird, a station of the U. S. Bureau of Fisheries on the McCloud River in Shasta County, California. The locality lies at present in the lower Transition zone at an elevation of 1500 feet above the sea. The surrounding country is well timbered with conifers, oaks, and maples in the main, and with lower scrub forming thickets in less favorable exposure. Topographically the region is rendered rather rough by numerous small tributaries of the McCloud River cutting through the Baird Shales, and the McCloud Limestones, to form canons with abrupt slopes and much dissected ridges. The cave occupies at present a position 800 feet above the McCloud River, only slightly over a mile away. According to the observations of Sinclair, the river flowed during the formation of the cavern deposits at approximately the level of the cave floor. The lowering of the river bed and the backward cutting of tributary streams brought about more rapid drainage of the country to either side of the cave, less water entered the fissure, and cave-cutting ceased. Openings were formed later in the roof of the cave by surface erosion, thus permitting the entrance of clay, rock fragments, broken bones and possibly of live animals. Subsequent uplift increased the cutting by streams in the region, and Potter Creek cut down through one of the galleries, thus forming the present cave entrance. There were two or three of these periods of uplift as deter- mined by Sinclair which changed the character of the country from one of moderate relief to one of mountainous aspect dis- s See Sinclair, W. J v Univ. Calif. Publ. Am. Arch. Ethn., vol. 2, pp. 1-27, 1904. 1912] Miller: Pacific Coast Avian Palaeontology 69 sected by river canons. The indications are that the actual elevation at present is considerably greater than that during the deposition of the bone-bearing material. Certainly the relation of the cave to the river level has changed in the neighborhood of eight hundred feet. There is no evidence of a later subsidence noted, so we may assume that the conditions during the period of deposition were more like those at Rancho La Brea than they are at present, i.e., less abrupt elevation and a smoother top- ography. The presence of Dendragapus in the cave deposits is an indication, however, that conditions were not identical in the two localities. A very interesting description of the various chambers and galleries of the cavern is given in Sinclair's paper. The fossil- bearing matrix represents the accumulation on the floors of the chambers and pockets in the form of fans of detritus, admitted doubtless through old chimney-like chutes now entirely blocked by limestone accretions and washed debris. These fans of ac- cumulated material were encrusted, and in some instances cemented, by stalagmitic deposits so that blasting had to be re- sorted to in places. The remains are in most cases entirely dissociated. Sinclair notes the finding of a few skeletons in their proper anatomical relations, such as those of a squirrel, a woodrat, a snake, and a bat. These are all animals which would go into caves of their own accord and after death fall upon the floors of the caverns. No case of bird skeletons in any degree associated is to be found. The bones have entirely lost their organic matter and appear almost as though calcined. Perfect bones of the smaller verte- brates are rare. In most cases fracture has occurred and in many the articular surfaces have been injured, either on account of the delicacy of the cancellated bone in that region, or because the presence of articular cartilages tempted the appetites of gnawing forms. Weathering and cracking due to exposure on the surface is the only reasonable explanation of the imperfec- tions of some specimens. Sinclair suggests three methods of possible introduction of animal remains into the cave. Washing by rills which carried bones from the surface down by way of the nearly vertical chim- 70 University of California Publications in Geology IT OL - 7 neys seems a very probable method. These open chimneys may have acted as pitfalls into which animals blundered in passing over the surface. Again, predatory forms may have carried their prey into the mouths of the caverns whence the accumulated bones were washed, or carried by woodrats, into the more remote recesses. This last method seems to the present author the most probable means of introduction of such forms as the anserines among birds. Falco peregrinus, whose remains also occur in the deposits, is a large and powerful hawk which habitually resorted to such places to nest. About the entrances to their nesting crevices today one commonly finds the ac- cumulated bones of a great variety of vertebrates brought as prey. Their predilection for the anserines has given these birds their common name of duck hawk. Sinclair records the following list of vertebrates from the Potter Creek Cave deposits, marking extinct species with an asterisk : SINCLAIR'S LIST OP SPECIES FROM POTTER CREEK CAVE *Arctotherium simum Cope. *Ursus, n. sp. *Felis, n. sp. Felis, near hippolestes Merriam, C. H. Lynx fasciatus Rafinesque. Lynx fasciatus, n. subsp. (?) Urocyon townsendi Merriam, C. H. Vulpes cascadensis Merriam, C. H. *Canis indianensis Leidy. *Taxidea, n. sp*. Bassariscus raptor Baird. Mephitis occidentalis Baird. *Spilogale, n. sp. Putorius arizonensis Mearns. Arctomys, sp. Sciurus hudsonicus albolimbatus Allen. Sciuropterus klamathensis Mer- riam, C. H. Spermophilus douglasi Richard- son. Eutamias senex (?) Allen. Callosp'ermophilus chrysodeirus Merriam, C. H. Lepus californicus Gray. Lepus klamathensis Merriam, C. H. Lepus, near auduboni Baird. Lepus, sp. *Teonoma, n. sp. Neotoma fuscipes Baird. Microtus californicus Peale. *Thomomys, n. sp. Thomomys leucodon Merriam, C. H. Thomomys monticola Allen *Aplodontia major, n. subsp. Scapanus californicus (?) Ayres. Antrozous pallidus Merriam, C. H. *Platygonus (?) sp. Odocoileus, sp. a. Odocoileus, sp 1 . b. Haplocerus montanus Ord. *Euceratherium collinum Sinclair and Furlong. * Species marked with the asterisk (*) are either extinct or are no longer represented in the region. 1912] Miller: Pacific Coast Avian Palaeontology 71 *Bison, sp. *Equus occidentalis Leidy. *Camelid. *Equus pacificus Leidy. *Megalonyx wheatleyi (?) Cope. Crotalus, sp. *Megalonyx jeffersonii (?) Har- Mylopharadon conocephalus Baird Ian. and Gerard. *Megalonyx, n. sp. Ptychocheilus (?) grandis (?) *Megalonyx, sp. (Ayres). * Mastodon americanus Kerr. Acipenser medirostris (?) Ayres. *Elephas primigenius Blumb. To this list of species published by Sinclair, the studies of the present author 9 would add the following birds : SPECIES OF BIRDS FROM POTTER CREEK CAVE Branta canadensis (Linnaeus). *Catharista shastensis Miller. Oreortyx picta (Douglas). Buteo borealis (Gmelin). Dendragapus obscurus (Say). Falco peregrinus Tunstall. *Bonasa umbellus (Linnaeus). Falco sparverius Linnaeus Indeterminate odontophorid. Otus asio (Linnaeus). *Meleagris, sp. *Bubo sinclairi Miller. *Gymnogyps amplus Miller. Colaptes cafer (Gmelin). Cathartes aura (Linnaeus). Corvus brachyrhynchos Brehm. * Species marked with the asterisk (*) are either extinct or are no longer represented in the region. Samivel Cave. Samwel Cave was explored by E. L. Fur- long, then of the University of California, who published an account of his work two years after the appearance of Sinclair's paper on the Potter Creek Cave. Furlong's account 10 pictures a cavern not essentially different from that described by Sin- clair. The conditions of interment seem to have been somewhat different, however, since there occurred a number of entire skele- tons of large and small carnivores and one form of ungulate, Preptoceras, which were preserved without fracture of the bones and in the proper anatomical relation. Furlong reaches the conclusion that the cavern was used as a lair by such forms as the bear and the cougar. To this lair the bodies of larger ungulates like Euceratherium and Preptoceras were dragged as prey. Some of the carcasses were left almost entire while others were torn to pieces and the bones more or less broken by the Miller, L. H., Univ. Calif. Publ., Bull. Dept. Geol., vol. 6, p. 385, 1911. 10 Furlong, E. L., Am. Journ. Sci., vol. 22, pp. 235-247, Sept., 1906. 72 University of California Publications in Geology [ V L - " teeth of the captor. The suggestion is also made that the cavern may have been used as a den for hibernation by various ursines, even as other caverns in the region are known to be used by bears of today. No specimen of bird skeleton was found with bones in proper place, so the probability is that the remains representing this class were introduced largely as in the case of the Potter Creek Cave specimens. Some essential difference must have existed, however, since the relation in numbers of the different species is so different in the two localities. The Cathartiformes appear in Potter Creek Cave represented by forty-five specimens distri- buted over three species. In Samwel Cave there appear but six specimens possibly assignable to the group. Falco percgrinus, represented in the former cave by four specimens, is wanting in the latter. The owls are represented by five specimens in the former and eleven in the latter, the grouse by thirty-four in the former as against one hundred and twenty-four in the latter. This difference of faunal proportions is perhaps most readily explained by the probable difference between the original open- ings of the caves. Let it be conceded that, as suggested by the respective authors, Potter Creek Cave opened by a relatively small chimney or two on the surface of the Pleistocene hillside and that Samwel Cave opened by a large chamber, the first part of which ran more nearly horizontally. Vultures, ravens, and the peregrine falcon nest in small cavities in rocky cliffs out of the way of small predatory mammals like the raccoons and the weasels. Their bones and those of their prey would accumulate in these pockets and eventually find their way into deeper re- cesses through fissures or chutes as described by Sinclair. The owls, however, resort to large open-mouthed caves to roost during much of the year, which fact would account for their greater abundance in Samwel Cave. Raccoons were found in abundance by Furlong as entire skeletons on the floor of Samwel Cave, thus suggesting that these animals frequented the place as a lair. The ground-dwelling birds, their natural prey, thus come to form a large proportion of the avian remains in these deposits. Procyonid forms are not listed by Sinclair from Potter Creek 1912 Miller: Pacific Coast Avian Palaeontology 73 Cave. They were either absent from the region or did not fre- quent the vicinity of the cave mouth. It seems not improbable that these small carnivores had a distinct relation to the num- ber of gallinaceous bird remains to become entombed in the various cave deposits. The following list of mammals is recorded by Furlong from the Samwel Cave: FURLONG'S LIST or SPECIES FROM SAMWEL CAVE Ursus americanus Pallas. Ursus, n. sp. Ursus, sp. Vulpes, sp. Uroeyon townsendi Merriam, C. H. Procyon, near lotor Linn. Putorius arizonensis Mearns. Mephitis occidentalis Baird. Mustela, sp. Felis, near hippolestes Merriam, 0. H. Aplodontia, near major Merriam, C. H. Aplodontia rufa Eafinesque. Erethizon epixanthus Brandt. Arctomys, sp. Lepus auduboni Baird. Lepus, sp. Thoraorays monticola Allen. Thomomys, sp. Microtus, sp. Neotoma fuscipes, Baird. Neotoma, sp. Citellus douglasi Richardson. Sciurus, sp. Euceratheriura collinum Sinclair and Furlong. Preptoceras sinclairi Furlong. Haplocerus, sp. Odocoileus, sp. a. Odocoileus, sp. &. Equus occidentalis Leidy. Elephas, sp. Megalonyx, sp. SPECIES OF BIRDS FROM SAMWEL CAVE. Indeterminate anserine a. Indeterminate anserine b. Indeterminate anserine c. Oreortyx picta (Douglas). Indeterminate odontophorid. *Gymnogyps amplus Miller. Cathartes aura (Linnaeus). *Catharista shastensis Miller. Accipiter velox (Wilson). Buteo swainsoni Bonaparte? Falco sparverius Linnaeus. Asio wilsonianus (Lesson). Bubo virginianus (Gmelin). *Bubo sinclairi Miller. Glaucidium gnoma Wagler. *Micropallas whitneyi (J. G. Cooper) . Colaptes cafer (Gmelin). Cyanocitta stelleri (Gmelin). * Species of birds marked with the asterisk (*) are extinct or else foreign to the locality. Hawver Cave. Hawver Cave is now located in the same faunal zone as the caves previously discussed and at about the same elevation, though some two degrees to the southward. The 74 University of California Publications in Geology [ VoL - 7 formation of the cave is essentially the same except that the work of solution is still probably going on to some extent. The method of entombment of the organic remains appeared to Fur- long to be the same as that acting in the case of Potter Creek Cave, i.e., the washing in of surface material by the action of streamlets. The presence of Megalonyx and Equus indicate the Pleisto- cene age of the bone-bearing deposits in the fissure. There ap- pear no remains of the large ungulates Euceratherium and Preptoceras to correspond with the deposits of the Shasta caves, but this condition may be more apparent than real, since but a limited amount of work was done in the cave before the level of the water in some of the passages rose to a point so high that access to the main bone-bearing chambers was prevented. But twelve species of birds are represented in the collections from this cave. Four of these are no longer represented in the region. The fact that the cave is still open and that changes due to the action of water are still going on lends a feeling of uncer- tainty a's to the exact age of any specimen. The association in loose material of remains which are unquestionably Pleistocene in origin with others representing still existing species is no guaranty of the age of the latter. There is continually going on a measure of differential motion in some of the debris ac- cumulated, which would possibly mingle fragments deposited at quite different times. Solution, shifting and re-cementing may have recurred several times although the excellent state of preservation of most of the bones would militate against the idea that a great deal of such movement had taken place. The few mammals thus far identified from Hawver Cave are listed as follows : Equus occidentalis (?) Leicly. Megalonyx, sp. Aplodontia, sp. Felis hippolestes Merriam, C. H. 1912] Miller: Pacific Coast Avian Palaeontology 75 LIST OF BIRDS FROM HAWVER CAVE. *Nettion carolinense (Gmelin). '*Geranoaetus melanoleucus Auct.f *Oreortyx picta (Douglas). *Colaptes cafer (Gmelin). *Lophortyx calif ornica (Shaw). *Cyanocitta stelleri (Gmelin). *Meleagris, sp. *Corvus corax Linnaeus. *Cathartes aura (Linnaeus). *Eup'hagus cyanocephalus (Wag- *Catharista shastensis Miller. ler). *Archibuteo ferrugineus (Lichten- stein). * An asterisk indicates that the species is extinct or no longer found in this region. Rancho La Brea. The Rancho La Brea beds constitute one of the most unique and at the same time one of the richest of Pleistocene deposits in the west; unique because in the entomb- ment of remains the factor of chance has been reduced to a minimum by the presence of an attractively baited and auto- matic trap ; rich because the trap was insatiable in its demands, because the material was promptly immersed and preserved in semi-fluid asphalt, and because of the fact that the trap was almost continually operative, it would seem, for a considerable period of time. According to Merriam, 11 who bases his conclusions on per- sonal observation and upon the opinions of Arnold, Orcutt, and other geologists, crude asphaltic oil from the underlying Fer- nando shales, here gently upfolded, has been forced to the sur- face through cracks or chimneys in these folded strata to ac- cumulate upon the surface as more or less extensive oil pools. This heavy oil, under the influence of sun and wind, underwent a process of natural distillation, becoming more and more viscid until in the larger accumulations it was sufficiently tenacious to entrap and hold the largest mammals of the region, Elephas, Mastodon, and Paramylodon. As pointed out by the same author, additions to these lenses of asphalt took place at the center as fresh oil rose through the chimneys from below; at the same time dust and sand drifted over and obscured the firmer asphalt of the margins. These two factors combined to bring about a most deceptive condition in the mass by leaving the periphery fairly firm and yet permitting a gradually increas- 11 Merriam, J. C., Mem. Univ. Calif., vol. 1, No. 2, pp. 199-213, 1911. 76 University of California Publications in Geology [VOL. 7 ing degree of plasticity toward the center without a positive de- marcation of the danger zone. Upon this treacherous surface a mammal would be unaware of danger until the dust-covered surface yielded under his weight. His sudden start or his leap for safety would make all the more complete his entanglement. While these exposed traps must have been in many cases pas- sive, concealed in an open or perhaps but slightly wooded locality where animals would blunder into them, they must often also have been actively attractive to animals through the two important factors of water and food. During a considerable period of time spent in working these fascinating deposits, the author has had frequent recourse to the water accumulated in depressions of the asphalt. This water has proven quite accept- able for drinking and for bathing. As algae accumulate, frogs, toads, dragonflies, mosquitoes, and other insect forms invade it; rushes and marsh-grass border the pools, their roots actually in contact with asphalt of the highest degree of tenacity. In a number of cases the asphalt accumulations represent depres- sions in the general surface of the country where not only the direct rainfall would be temporarily held empounded but more lasting pools representing surface drainage or even seepage would accumulate. The presence of bedded leaf-masses and of water-worn fragments of wood intermingled with the animal remains would support the view that there were at times ponds of a more or less permanent nature. The animals of poorly watered regions in the southwest are perforce far from fas- tidious in the matter of drinking water; hence the herbivorous mammal must certainly have found the vicinity of these water pools one offering very positive attraction as to water and perhaps grass as well. The entanglement of one ungulate would suffice to attract a multitude of carnivores. The creature probably acted not infrequently as live bait for a considerable time, so that its struggles and outcries served to whet the appetites and overcome the instincts of caution in the hungry carnivore. It appears from Merriam's studies that young animals or else old or dis- eased individuals have very frequently been thus tempted, though there appear animals of all ages. 1912] Miller: Pacific Coast Avian Palaeontology 77 The prevailing conditions also led to a greatly distorted relation between predaceous and non-predaceous species in point of numbers. While removing a single femur of Paramylodon there were found touching it three complete skulls of Canis indianensis, and even this proportion of three to one is much too small to represent the facts truthfully. In a collection of bird remains made by the writer the number of specimens of Aquila exceeds the number representing all the non-raptorial species combined, while fifty-six per cent of the species recorded are predatory. The cessation of struggling on the part of the entrapped animal did not end its services as trap bait. Some forms which normally seek an active prey, e.g., Canis and Aquila, may on occasion resort to carrion. A decrepit wolf or a hungry eagle may not infreqently thus supply the demands of necessity. The odors emanating from these pits where freshly excavated are, to human nostrils, strongly suggestive of carrion. Gases exhaled by animal bodies submerged in the plastic mass would accen- tuate this olfactory effect to such a degree as probably to attract carrion feeders. Was this influence also felt by birds? Dar- win's well-known experiments on Andean condors kept in cap- tivity have long been accepted as proving that the vultures do not employ the olfactory sense in the perception of food. How- ever, the experiences of later naturalists with Cathartes, which is often caught in wolf-traps with concealed bait, leads us to emphasize the fact that Darwin was experimenting with birds in captivity which had been fed perhaps from early youth in more or less regular fashion. We must at least concede it possible that the abundant vulture remains in the asphalt are the result in part of this factor of odor in attracting them to the locality. 78 University of California Publications in Geology [VOL. 7 PARTIAL LIST OF MAMMALS FROM EANCHO LA BREA. *Canis indianensis Leidy. *Canis orcutti Merriam, J. C. *Canis andersoni Merriam, J. C. *Canis occidentalis furlongi Mer- riam, J. C. *Lynx occidentalis fischeri Mer- riam, J. C. *Felis atrox bebbi Merriam, J. C. *Smilodon californicus Bovard. Mephitis, sp. Putorius, sp. *Arctotherium californicum Mer- riam, J. C. *Elephas, sp. *Mastodon, sp. *Equus, sp. *Bison antiquus Leidy. *Capromeryx minor Taylor. *Camelops (?), sp. *Paramylodqn, sp. SPECIES OF BIRDS KNOWN FROM RANCHO LA BREA. Haliaetus leucocephalus (Lin- naeus) . *Morphnus woodwardi Miller. *Geranoaetus grinnelli Miller. *Geranoaetus fragilis Miller. Falco p'eregrinus Tunstall. Falco, sp. Falco sparverius Linnaeus. *Polyborus tharus Auct. Alueo pratincola (Bonaparte). Asio flammeus (Pontoppidan). Otus asio (Linnaeus). Bubo virginianus (Gmelin). Speotyto cunicularia hypogaea (Bonaparte). *Neomorpha, ? sp. Colaptes cafer (Gmelin). Otocoris alpestris (Linnaeus). Corvus corax Linnaeus. Corvus brachyrhynchos Brehm. * Corvus, sp. Xanthocephalus xanthocep'halus (Bonaparte). Agelaius gubernator (Wagler). Sturnella neglecta Audubon. Pipilo, sp. Lanius ludovicianus Linnaeus. * Species marked with an asterisk (*) are extinct or foreign to the locality. Fossil Lake. The horizon designated by Cope as Silver Lake and classed collectively with several other m horizons as the Equus Beds, was thought for many years to be of Pliocene age and as such was considered by Cope and by Shufeldt in their studies Chaulelasmus streperus (Lin- naeus). Anser albifrons (Scopoli) ? Branta canadensis (Linnaeus). *Cieonia maltha Miller. Jabiru mycteria (Lichtenstein). Mycteria americana Linnaeus. Ardea herodias Linnaeus. *Grus minor Miller. Grus canadensis (Linnaeus). Lophortyx sp. *Meleagris ? *Pavo californicus Miller. Gymnogyps calif ornianus (Shaw). *Sarcorhamphus clarki Miller. *Pleistogyps rex Miller. *Cathartornis gracilis Miller. Cathartes aura (Linnaeus). *Catharista occidentalis Miller. *Teratornis merriami Miller. Elanus leucurus (Vieillot). Circus hudsonius (Linnaeus). *Circus, sp. Buteo, sp. Buteo borealis (Gmelin). Aquila chrysaetos (Linnaeus). 1912] Miller: Pacific Coast Avian Palaeontology 79 of the birds from that region. Our knowledge of the various western horizons has, however, been extended by later investiga- tors in stratigraphy and in the correlation of faunas, with the result that these beds are now proven unquestionably to be of Pleistocene age. Such change of interpretation alters materially the significance of discoveries announced by Cope and by Shu- feldt in that it reduces appreciably the extent to which several existing genera are known to run back in time. The various descriptions of this, region are summarized in a concise and very lucid paragraph or two by Osborn 12 from which the following may well be quoted : "One hundred and fifty miles northwest of the old Lahontan shore lines in the heart of the Oregon Desert of the great basin, and twenty miles northeast of Silver Lake, there is a slight depression in the desert perhaps twenty acres in extent marked Christmas Lake on the maps, to which Cope gave the name 'Fossil Lake.' This ' Silver/ 'Christmas,' or 'Fossil' lake region was successively explored by Condon, Cope, Sternberg (who made the chief collections), and Eussel (1882). . . . Though actually twenty miles distant from Silver Lake, the rich fauna of mammals and birds found has been described by Copei3 and Shufeldt, and referred to by Gilbert, as the fauna of the Silver Lake Equus beds. . . . "Proof that the country was partly fluviatile and partly wooded is afforded by the presence of the muskrat (Fiber}, the otter (Lutra), the beaver ( Castor fiber), and the giant beaver (Castoroides) . " .... The bird life was very abundant and not very dissimilar from what we might observe at any of the alkaline lakes of the West, resorted to at the present day by wild fowl during their migrations. Great flocks of swans (Cygnus paloregonus) , geese (Anser condoni), and ducks were there; a cormorant (PTialacrocorax) was among the rarities; among the species of grebe (Podiceps occidentalis) is one still inhabiting this region. There were also coots (Fulica minor) and herons (Ardea paloccidentalis) . Other forms of birds include two species of grouse, crows, and eagles. The strangest figure upon the scenes among the birds was a true flamingo (Phoenicopterus copei}. The northernmost distribution of flamingoes at the present is southern Florida and the Bahama Islands (lat. 27 N). Shufeldt concludes that the climate might well be compared with that of Florida or the lower part of Louisiana, that the vegetation was fully as luxuriant as it now is in those parts, and that the palms were abundantly represented. This conclusion as to a Floridan climate and the existence of palms is, however, very questionable. Brown 14 observes that the South American flamingoes (Phoenicopterus chilensis} migrate as far south as 12 Osborn, H. F., The Age of Mammals, p. 458. is Cope, E. D., The Silver Lake of Oregon and its Region, Am. Nat., vol. 23, pp. 970-982, 1889. 14 Mr. Barnum Brown in a note to the author [Osborn]. 80 University of California Publications in Geology [VOL. 7 the lakes in central eastern Tierra del Fuego, lat. 53 S, where they are said to breed, and certainly spend a part of the season. This region cor- responds in temperature to the climate of central Alberta, Canada, 400 miles north of Silver Lake. Thus it appears that the presence of Phoenicop- terus copei at Silver Lake has very little weight in the determination of climate. It is more probable that the northern lakes of that period con- tained mollusks on which the flamingoes fed. ' ' Aside from an extinct genus of grouse, Phoenicopterus is the only genus recorded fossil that might not reasonably be expected to occur in the region at the present time. Shufeldt's original paper 15 gives a detailed description of most of the species of birds found in the Fossil Lake beds and a synoptical list of the known species was published in a paper by the writer 16 as follows: ^chmophorus occidentalis (Lawrence) Pygopodes : Lougipennes : Steganop'odes : Anseres : yEchmophorus occidentalis (Lawrence). Colymbus holboelli (Eeinhardt). Colymbus auritus Linneus. Colymbus nigricollis calif ornicus (Heermann), Podilymbus podiceps (Linneus). Larus argentatus Pontoppidan. Larus robustus Shufeldt. Larus californicus Lawrence. Larus oregonus Shufeldt. Larus Philadelphia (Ord). Xema sabini (J. Sabine). Sterna elegans Gambel. Sterna forsteri Nuttall. Hydrochelidon nigra surinamensis (Gmelin). Phalacrocorax macropus (Cope). Pelecanus erythrorhynchos Gmelin. Lophodytes cucullatus (Linnaeus). Anas platyrhynchos Linnaeus. Mareca americana (Gmelin). Nettion carolinense (Gmelin). Querquedula discors (Linnaeus). Querquedula cyanoptera (Vieillot). Spatula clypeata (Linnaeus). Dafila acuta (Linnaeus). Aix sponsa (Linnaeus). is Shufeldt, E. W., Journ. Acad. Nat. Sci. Phila., ser. 2, no. 9, pp. 389- 45, 1892. is Miller, L. H., Univ. Calif. Publ., Bull. Dept. Geol., vol. 6, pp. 79-87, 1911. 1912] Miller: Pacific Coast Avian Palaeontology 81 Marila valisineria (Wilson). Clangula islandica (Gmelin). Harelda hyemalis (Linnaeus). Anser condoni Shufeldt. Anser albifrons gambeli Hartlaub. Branta hypsibata Cope. Branta canadensis (Linnaeus). Branta propinqua Shufeldt. Chen hyperboreus (Pallas). Olor paloregonus (Cope). Odontoglossae : Phoenicopterus copei Shufeldt. Herodiones: Ardea paloccidentalis Shufeldt. Paludicolae: Fulica americana Gmelin. Fulica minor Shufeldt. Limicolae: Lobipes lobatus (Linnaeus). Gallinae: Tympanuchus pallidicinctus (Ridgway). Pedioecetes phasianellus columbianus (Ord). Pedioecetes lucasi Shufeldt. Pedioecetes nanus Shufeldt. Palaeotetrix gilli Shufeldt. Accipitres: Aquila pliogryps Shufeldt. Aquila sodalis Shufeldt. Striges: Bubo virginianus (Gmelin). Passeres: Euphagus affinis Shufeldt. Corvus annectens Shufeldt. ADDITIONAL SPECIES OP BIRDS IN THE CALIFORNIA COLLECTIONS Pygopodes: ^chmophorus lucasi Miller. Anseres: Erismatura jamaicensis (Gmelin). Accipitres: Circus hudsonius (Linnaeus). ~~_ PARTIAL LIST OF MAMMALS FROM FOSSIL LAKE.I? Ursus, sp. Felis, sp. Canis latrans Say. Canis, cf. occidentalis Richardson. ftVulpes, cf. pennsylvanicus Bodd. Lutra canadensis Schreber. Fiber zibethicus Linnaeus. Arvicola, sp. Thomomys, sp. Ueomys, sp. Castor, sp. Castoroides, sp. Lepus, sp. Mylodon sodalis Cope. Equus pacificus Leidy. Equus, n. sp. Elephas, sp. Platygonus, cf. vetus Leidy. Platygonus, sp. Eschatius conidens Cope. Camelops kansanus Leidy. Camelops vitakerianus Cope. Camelops, sp. Antilocapra, sp. 17 Sinclair, W. J., Univ. Calif. Publ. Am. Arch. Ethn., vol. 2, p. 1, 1904. 82 University of California Publications in Geology [Vo L - 7 Rodeo Pleistocene. Almost nothing has been recorded con- cerning this formation. The region has been repeatedly visited by parties from the University of California and the Pleistocene age of the beds definitely established. The single specimen of bird remains from the locality was picked up at the base of the exposure by Professor J. C. Mer- riam with parts of the matrix of the Pleistocene beds still adher- ing to it. The bone is a perfect tarsometarsus of average size. SINGLE SPECIES FROM EODEO PLEISTOCENE. 2Echmophorus occidentalis (Lawrence). PRESENT PHYSIOGRAPHIC AND GEOGRAPHIC RELATIONS OF THE WEST AMERICAN REGIONS IN WHICH FOSSIL AVIAN REMAINS ARE KNOWN The nine localities referred to above have yielded several thousand specimens in all. Only five of these specimens, repre- senting three species, are from deposits older than the Pleisto- cene ; hence we may consider our knowledge as practically limited to that age. Since also the systematic groups larger than the species display in the case of birds such remarkable longevity, time relations between the several Pleistocene horizons become of minor importance except as we learn of variations in climate during that period. There is on the other hand an advantage to be derived from the approximate contemporaneity of the deposits. The entomb- ment of many specimens at about the same time under a variety of conditions and in a number of different localities gives us an unusually accurate conception of the avifauna of that time. The Fossil Lake deposits yield mainly those species to be found about open, shallow lakes; the caverns are so located as to h entombed those species which inhabit lower mountainous coun- try ; the Rodeo Pleistocene consists of seashore accumulation ; the Rancho La Brea beds a.re the result of a peculiarly diverse com- bination of circumstances which led to the trapping of open- plains birds with a preponderance of raptorial species. The asphalt beds lie in latitude 34 N, on the coastal side of the Santa Monica Mountains within a few miles of the sea and 1912] Miller: Pacific Coast Avian Palaeontology 83 less than two hundred feet above its level. The -locality is today a typical open valley country, protected on the north by the east-and-west Santa Monica Range, yet tempered by the cool and moisture-laden breeze from the sea. Faunally, the locality lies in the Upper Sonoran zone of the San Diego region. The Shasta caves occupy a position further inland and seven degrees to the northward of Rancho La Brea. Their elevations vary between 1300 and 1500 feet above sea-level. The isothermic zone represented is slightly above that of Rancho La Brea, it being Upper Sonoran and lower Transition. The isohumic area is that of the Sacramento-San Joaquin, which is an area of slightly greater precipitation than is the San Diegan. The two localities are at present distinguishable in their avi- fauna by the presence or the absence of several species which are of interest in the light of palaeontological records. . The entire group of grouse, represented in the Shasta region by Dendragapus, is wanting at Rancho La Brea. Oreortyx and Cyanocitta, present in the cave region, are wanting in the im- mediate vicinity of the asphalt beds. Geococcyx, present in the latter locality, is wanting in the former. These, however, are birds of slight volant power. The species of less restricted activity, such as the Raptores and the water- birds, are common to the two localities at present. The Fossil Lake region of Oregon lies in latitude 43 N, full nine degrees north of Rancho La Brea, and is on the eastern side of the Cascade Range. This separation from the coastal slope would influence the smaller species of birds more than the larger. Winter temperatures would be more severe, with sum- mer temperatures fully equal to those of southern California. The rainfall at the present time is such as to give the region the name of ''Oregon Desert." There appears, then, as distinguishing the five more import- ant localities today, a difference of nine degrees of latitude, a range of elevation from 100 to 1500 feet above the sea, and a faunal difference limited to the Upper Sonoran and lower Transition zones. There is no evidence of marked change in elevation since Pleistocene times; hence it seems probable that a somewhat similar relationship between the localities prevailed 84 University of California Publications in Geology [VOL. 7 during the Pleistocene period and that the specimens obtained from the various horizons represent in the aggregate, with a considerable degree of accuracy, the avifauna of the Pacific coast at that time. RELATION OF PLEISTOCENE FAUNAS TO THOSE OF THE PRESENT DAY A partial list of the Recent birds of the Transition zone in the Shasta region is given in the report of a biological survey of the region by C. H. Merriam. 18 The list is appended here and the more striking differences displayed by the other locali- ties are noted. This comparison may prove of interest in con- sidering the fossil avifauna. EECENT AVIFAUNA OF THE SHASTA REGION (Partial list from Upper Sonoran and Transition zones) Oreortyx picta (Douglas). Lophortyx calif ornica (Shaw). Dendragapus obscurus (Say). Zenaidura macroura (Linnaeus). Cathartes aura (Linnaeus). Circus hudsonius (Linnaeus). Buteo borealis (Gmelin). Aquila chrysaetos (Linnaeus). Falco mexicanus Schlegel. Falco sparverius Linnaeus. Bubo virginianus (Gmelin). Speotyto cunicularia (Molina). Glaucidium gnoma Wagler. Colaptes cafer (Gmelin). Aphelocoma californica (Vigors). Cyanocitta stelleri (Gmelin). Sturnella neglecta Audubon. Euphagus cyanocephalus (Wagler). Lanius ludovicianus Linnaeus. Planesticus migratorius (Lin- naeus). To this list may be added the following species which possibly occur in the locality, though not recorded by the collectors of the survey party: Accipiter velox (Wilson). Accipiter cooperi (Bonaparte). Astur atricapillus (Wilson). Buteo swainsoni Bonaparte. Archibuteo ferrugineus (Lichten- stein). Haliaetus leucocephalus (Lin- naeus). Gymnogyps calif ornianus (Shaw). Falco peregrinus Tunstall. Aluco pratincola (Bonaparte). Asio wilsonianus (Lesson). Otus asio (Linnaeus) . Geococcyx calif ornianus (Lesson). Corvus corax Linnaeus. Corvus brachyrhynchos Brehm. Cosmopolitan water birds is Merriam, C. H., Eesults of a Biological Survey of Mt. Shasta, Cali- fornia, N. Am. Fauna, No. 16, 1899. 1912] Miller: Pacific Coast Avian Palaeontology 85 SOME RECENT BIRDS NOTED IN THE SILVER LAKE REGION. Geese, Swans, Pelicans, Cormorants Oreoscoptes montanus (Townsend, ^chmorphorus occidentalis (Law- J. K.) rence). Asyndesmus lewisi Riley. Myadestes townsendi (Audubon). Eecurvirostra americana Gmelin. Ixoreus naevius (Gmelin). Himantopus mexieanus (Miiller). If, as is suggested by the configuration of the country, the former elevation of the caves was slightly less than at present and the country less broken, conditions were then more favor- able than at present for such species as Geococcyx californianus and Archibuteo ferrugineus. The probability that slow-moving streams and small lakelets served to attract waders, anserines, and Haliaetus would be greater in such a condition of the coun- try. In the vicinity of Fossil Lake, Oregon, the present avifauna would show probably several points of divergence from the cave region and from Rancho La Brea. Oreortyx, Cyanocitta, Aphe- locoma, and Geococcyx would probably be lacking, while one would doubtless meet with Pedioecetes, Centrocercus and Cyano- ceplialus. At Rancho La Brea, Elanus and Geococcyx would prove more abundant, Agelaius, Xanthocephalus, and Otocoris would be plentiful, while Dendragapus, Oreortyx, and Cyanocitta would not be likely to occur. Elanus and Geococcyx at Rancho La Brea, Dendragapus in the Shasta region and Centrocercus and Pedioecetes in the Fossil Lake region are the chief differences dependent upon latitude to be noticed among the three faunas. The other discrepancies are such as would be due to slight differ- erence in altitude, the proximity of water or the topography" of the region. The long list of smaller passerines, piciforms and machro- cheirs is here purposely omitted, since they, though very im- portant in the determination of faunal zones, seem not to have been preserved in the fossil state to any great extent. Distribution of the Cathartidae. One of the groups of chief interest in discussing the subject of distribution in the light 19 Cope, E. D., The Silver Lake of Oregon and its Region, Am. Nat., vol. 23, p. 970, 1839. 86 University of California Publications in Geology [V L - 7 of palaeontological study is the raptorial subdivision embracing the New World vultures. The exclusive possession by the Americas of so marked a group of large and strong-flying birds as the Cathartidae and the total absence there of any form of the true Vulturidae, which occupy the same bionomic position in the Old World, is one of the striking phenomena in animal distribution. Aside from the fact that the group is so well defined, there being no Recent forms showing transition between it and the other raptorine subdivisions, we find it not poor in species and it is widely distributed in the western hemisphere. There are endemic to the New World no less than five distinct cathartine genera a goodly number for a group, the smallest member of which approaches in size the largest eagles. All are birds capable of long-sustained flights and they are unsurpassed in their ability to meet the emergencies of changed elevation and shifting air currents that would prove disturbing to less perfect fliers. This very factor may, by insuring them against being driven astray by storms, bring about a distribution more in accord with their own needs or inclinations. As an instructive comparison in the matter of distribution one might consider the short-eared owl (Asio flammeus). This bird is almost cosmopolitan, occurring unmodified over both hemispheres and even in such isolated islands as the Hawaiian group, though no more maritime and no more capable a flier than the cathartid vultures. It might be suggested as a dis- tinction between these two cases that the vultures are non- migratory and are confined to the tropics, and would, therefore, have no tendency to wander, would not be exposed to the danger of scattering by storms and would always be separated from the other continents by the widest parts of the ocean basins. An examination of the ranges and the habits of the existing species will, however, prove the fallacy of such views. Cathartes aura is migratory or not as occasion demands. It is resident to 40 N latitude and thence northward ,it becomes migratory, being starved out in winter. Its habitual range extends from 55 N latitude to Tierra del Fuego and the Falkland Islands on the south. 20 20 Coues, E., Key to N. Am. Birds (ed. 5; 1903), vol. 2. 1912] Miller: Pacific Coast Avian Palaeontology 87 Other members of the group range as follows: The Andean condor (Sarcorhamphus) occurs along the Cordillera from equatorial Peru to the extremity of Patagonia and from sea- level to the highest summits of the Andes; Catharista urubu inhabits the whole of tropical America, southward to Argentina and northward as a straggler to the Canadian border ; the two remaining genera, Gyparclms and Gymnogyps, occupy succes- sively more circumscribed areas. Not, however, till the latter was so nearly exterminated by human agency, was either form of restricted range. Gymnogyps is confined entirely to the Nearctic realm, Sarcorhampkus is entirely Neogaeic, but the three remaining forms are distributed without regard to realm and all are independent of the generally recognized life-zones. That a group thus distributed, many of whose members are so in- dependent of climatic and of minor geographic barriers, should be limited to the western hemisphere seems indeed strange. The influence of a virile and aggressive species is not infre- quently effective as a barrier to the distribution of a less active one and it may be urged that the slightly more rapacious vul- turines of the Old World have served as a check upon any ten- dency of the cathartids to diffuse into Eurasia. Such a view is controverted by the fact that the latter birds prove themselves perfectly able to maintain their existence in competition with the polyborine scavengers which, in a .way, represent the Old World vultures in their habits. With the geographical limitations of the group before us, the question of ancestry and the geological record assume a very important aspect. Concerning the antiquity of the group there is unfortunately but little known. Previous to the opening up of the Rancho La Brea deposits in California, fossil cathartids of unquestionable identity were unknown to North America. Cope's Palaeoborus umbrosus^ from the Pliocene of New Mexico, which he orig- inally placed in the genus Cathartes, he later transfers to the genus Vultur. The new genus Palaeoborus was established by Coues for its reception since " .... the description and figures 21 Cope, E. D., U. S. G. Surv. W. of 100th MericL, vol. 4, pt. 2, p. 287, 1876. 88 University of California Publications in Geology [VOL. 7 clearly indicate a bird generically distinct from Cathartes and the improbability of the occurrence of a true Vultur in North America is extreme. ' ' 22 With the former point at least there can be no possible disagreement after a consideration of Cope 's figures of Palaeoborus. Whether the form may be considered cathartine at all is open to. very serious question. Lucas 23 considers it as more probably of polyborine affinities. In South America fossil cathartids are less rare. Cathartes and Gyparchus are reported from the Pleistocene caves of Brazil. 24 Moreno and Mercerat 25 describe two species from the Pampean Pleistocene and three from the Pliocene of the Santa Cruz. The Pleistocene species, Cathartes fossilis and Sarco- rhamphus fossilis, represent genera still existing in that region. The three species from the Santa Cruz, Psilopterus communis, P. australis and P. intermedius, belong to an extinct genus which is placed by the authors adjacent to Cathartes and is considered by them to be intermediate or transitional between that genus and Sarcorhamphus. The three species of Psilopterus are based on the most fragmentary material. The figures are such as to indicate specimens in rather poor state of preservation as to sur- face markings. Trochleae are corroded away and intermuscular lines are entirely wanting. P. intermedius is based on a single specimen consisting of two tarsal trochleae. The other two species are based upon fragmentary tarsi poorly preserved. While there may be no question in the minds of these authors as to the relationships of the genus Psilopterus, there appears nothing in the lithographed figures or in the very meager descrip- tions that is at all convincing. Beyond the above instances, the only record of fossil cath- artids previous to the excavations at Rancho La Brea is the remarkable specimen made known by Gaillard 26 from the phos- phorites of Quercy, an Oligocene horizon in France. This species, 2-2 Coues, E., Key to N. Am. Birds (ed. 2; 2884), p. 822. 23 Lucas, F. A., in Zittel's Text-Book of Palaeontology, Eng. trans., vol. 2, p. 277, 1902. 24 Winge, O., Fugle fra Knoglehaler i Brazilien, Museo Lundii, 1887. 25 Palae. Argentina, An. Mus. La Plata, pt. 1, p. 67, 1891. 26 Gaillard, C., Ann. de 1 'Univ. de Lyon, n. ser. 1, Sc. & Med., fasc. 23, 1908. 191 2] Miller: Pacific Coast Avian Palaeontology 89 Plesiocarthartes europeus Gaillard, thus becomes at once the most ancient cathartid, and the only instance known to the author of the occurrence, fossil or Recent, of the family outside the American continents. The species, as far as can be learned, is represented by a single bone, a fragmentary tarsometatarsus preserved in the Museum of Lyons. The specimen is, however, sufficient to establish beyond question the cathartine relation- ships of the species. Its author considers the case to be one of an individual's having straggled from its normal range. In view of the extensive examination of most of the European horizons which has failed thus far to furnish evidence of its further occurrence there, the conclusions reached by Dr. Gail- lard may be considered as probably correct. With the progress of work at the University of California our knowledge of the group under discussion is considerably advanced. In the collections from Fossil Lake the abundant avian remains are almost entirely of aquatic forms, although there appear in the University collections, as well as in the much larger Cope and the Condon collections, a number of raptorial species. There are, however, no specimens referable to the Cath- artidae, a rather conspicuous absence. There appears no reason deducible from the habits of the turkey, vulture of today why, if vultures were present during the formation of these beds, their remains should not have been preserved there. In fact, there is every reason for considering the vulture a more favorable subject for preservation in such deposits than are the other raptors. The turkey vulture is one of the commonest of beach-combers along the shores of both fresh and salt-water bodies and it comes habitually in great flocks to spend the warmer parts of the day wading in the shallower waters or sitting about the sand bars of quiet streams. The negative evidence very strongly suggests the absence of cath- artids from the region during the deposition of the Fossil Lake beds. Potter Creek and Samwel caves both furnish remains of these vultures, while the Rancho La Brea asphalt is especially rich in raptorial species, about equally divided between the cath- artids and the falconids. 90 University of California Publications in Geology [VOL. 7 At Rancho La Brea there occur six truly cathartine species as follows: Gymnogyps calif ornianus, Sarcorhamphus clarlci, Cathartornis gracilis, Pleistogyps rex, Cathartes aura, and Cath- arista occidentalis. Besides these forms, the aberrant Teratornis is nearer to the Cathartidae than to any other family at present recognized. In the cave deposits there appear the two forms, Catliarista shastensis and Gymnogyps amplus, belonging to ex- isting genera. The condors and Teratornis represent the extreme of spe- cialization in point of size, the greatest degree of diversity, and possibly also the least specific longevity. Gymnogyps calif orni- anus alone of the six larger forms has persisted unchanged from the time of formation of the asphalt beds, where it is the most abundant of the condors, until the present time, when it seems on the verge of extinction. Probably its associates of that time had passed the prime of their specific existence while the present form, less specialized toward gigantism, constituted a younger development reaching its maximum of virility later than its congeners but becoming decadent by the present time. As a result of the excavations at Rancho La Brea the genus Catliarista became known to the Pleistocene of North America, its first discovery in the fossil state. Its range was at the same time extended from its previous limits the tropical and lower Austral zones of both continents to include the Pacific Coast region of California, an area at present occupied by an Upper Sonoran fauna. The fossil species C. occidentalis is found in great abundance in the asphalt. Its relative abundance as com- pared with the other vultures there is shown by a census of an unassorted collection of the bird remains, which gave the fol- lowing results : Gymnogyps californianus 11 individuals Cathartes aura 20 individuals Catliarista occidentalis 21 individuals As indicated in the note descriptive of Catharista occidentalis, the difference between the fossil and the Recent forms lies in the greater body size of the fossil form accompanied by a difference in proportion of the segments of the posterior limb. The tarsus Polyborus there appear the following fossil forms whose nearest 1912] Miller: Pacific Coast Avian Palaeontology 91 shows a greater degree of robustness, both absolute and relative. The humerus is slightly longer and stouter, but whether the wing expanse is increased to a degree commensurate with the in- creased body weight is questionable. We seem, then, to be deal- ing with a vulture that was of a heavier body and shorter limb than the persistent Catharista urubu. The difference be- comes more significant when it is noted that the character separ- ating the extinct from the persistent species of Catharista is identical with one of those separating the more restricted Cathar- ista urubu from the wider ranging Cathartes aura. It should also be noted that the extinct form Catharista shastensis from the caves is separable from the Rancho La Brea species, C. Occi- dent alis, by a greater robustness of the tarsometatarsus and by a greater body size as indicated by its stouter coracoid. The cave form, the asphalt form, and the Recent form of Catharista thus fall with the Recent Cathartes into a series of progressively lighter-bodied and possibly more strongly flying vultures, which display, in the cases of the last three at least, a progressively greater ability to cope with their environment. That the cavern and the asphalt deposits are 'not of the same age is evidenced by the occurrence therein of distinct but closely related species of cathartids belonging to two genera, i.e. Gym- nogyps and Catharista. The localities are separated by approx- imately seven degrees of latitude and a difference in elevation of fourteen hundred feet. Both lie at present in approximately the same faunal zone. Species possessed of the excellent volant powers shown by the large vultures when present in the con- siderable numbers indicated by their remains in the two deposits would scarcely feel the restrictions of such slight barriers as could have existed at that time. The existing species of Gymnogyps, before its numbers were depleted by the influence of man, ranged from Lower California to British Columbia and from sea-level to the summits of the Coast Range, while the existing Cathartes is almost ubiquitous. Furthermore our knowledge of the Recent vultures as a group would lead us to discard as incongruous the conception of a vulture so strictly boreal as to come southward in considerable numbers as far as the Shasta region and not reach the more 92 University of California Publications in Geology [V L - 7 favorable environment of Southern California. We must, then, almost of necessity conclude that the separation of the two faunas is due to difference in time rather than to any other factor. The two horizons have in common with the Recent North American fauna three cathartine genera, viz., Cathartes, Cath- arista, and Gymnogyps. Catharista, at present foreign to the immediate vicinity, is represented in the two deposits by distinct species. Gymnogyps calif ornianus is abundant in the asphalt beds and in the Recent fauna of a region including and extend- ing far beyond both localities, yet the genus is represented in the cave deposits only by a distinct species, G. amplus. It is hard to explain how the cavern deposits could have been inter- polated between the Rancho La Brea horizon and the Recent and still possess two distinctive cathartine forms and only one, Cathartes aura, in common with either of them. Distribution of Falconidae. Palaeontology has added mate- rially to our knowledge of this group in at least two respects, namely in our concepts of the former distribution of its members and of the degree of adaptive radiation that has taken place within its limits. The three genera Geranoaetus, Morphnus, and Polyborus, limited in Recent time to tropical or to south tem- perate America, are now known to have ranged in the previous period well up into California. Geranoaetus went as far north as Hawver Cave and the other two as far as Los Angeles. The larger phase of Haliaetus, which is limited at present to the northern parts of North America, had not at the time of deposi- tion of the asphalt beds withdrawn to the northward as a distinct geographical race. The remains of Haliaetus leucoce- phalus from these beds embrace in their range of variation ex- tremes of size surpassing at either end of the scale the two existing races, H. I. alascanus and H. I. leucocephalus now geo- graphically distinct. As illustrative of the number of adaptive radiations of the eagle group we may point to the six fossil eagles of Marsh, Shufeldt, and Miller. These are as follows: Aquila sodalis, A. pliogryps, A. dananus, Morphnus woodwardi, Geranoaetus grin- nelli, and G. fragilis. Besides these extinct forms there were found fossil the three persisting species Aquila chrysaetos, 1912] Miller: Pacific Coast Avian Palaeontology 93 Haliaetus leucoceplialus, and Geranoaetus melanoleucus. Aquila pliogryps Shufeldt is described from a single bone, the basal phalanx of the right hallux. The species is considered to be slightly larger but more slender-limbed than Aquila chrysaetos. The material representing the species is so limited that no clear impression of its closer relationships can be formed. Morph- nus woodwardi from Rancho La Brea may well have been such a bird, though there is no way of obtaining more than the sug- gestion of similarity from the fact that they were both eagles of slender build. The statement made by Shufeldt is that Aquila pliogryps was slender of foot, as indicated by the slightly longer digits. Morpknus is a genus of long-shanked eagles with rela- tively weak feet, as indicated by the size of the trochleae. The digits certainly must have been much smaller in Morplinus wood- wardi than in Aquila chrysaetos or in A. pliogryps. Shufeldt 's species, A. sodalis, is founded on the proximal part of a tarsometatarsus. The specimen is figured from the anterior aspect drawn to natural scale. Compared with the Rancho La Brea eagles, A. sodalis corresponds quite closely in size with Geranoaetus fragilis, the smallest of the group there represented. A. sodalis seems, however, to be of an entirely dif- ferent nature if the position of the papilla of the tibialis anticus may be taken as indicative. In a discussion of the splendid series of eagle tarsi from the asphalt, it has been pointed out by the author 27 that the position of this tubercle seemed to bear a very definite relation to the slenderness of the tarsus, i.e., the long-shanked forms have the tubercle placed high up on the shaft of the bone. Applying this principle to Shufeldt 's figure of A. sodalis, it would seem that the Fossil Lake species was not of the same group of eagles as the more southern genera Morphnus and Geranoaetus assembled by Ridgway under the caption Morphni. In A. sodalis the papilla of the tibialis anticus is placed farther down the shaft and the proximal foramina are separated by a much wider space. Unfortunately the charac- ter of the Itypotarsus is not shown in Shufeldt 's figure of Aquila sodalis nor is an accurate impression of the region obtainable from the description. It seems proper to consider the two species Miller, L. H., Univ. Calif. Pub!., Bull. Dept. Geol., vol. 6, p. 305, 1911. 94 University of California Publications in Geology [V L - 7 described by Shufeldt as distinct from any of the Rancho La Brea forms. Aquila dananus Marsh 28 is described as being slightly smaller than the existing A. ckrysaetos. A single specimen of the species was taken in the Loup Fork of Nebraska. It consists of the distal part of the tibia only and is not figured by Marsh in the original description. The assignment of the specimen to the genus Aquila is proper in the absence of any feature to dis- tinguish it from that genus. The suggestion of the possible identity of one of the Fossil Lake forms, A. sodalis, with Marsh's A. dananus is made in Shufeldt 's paper but that author con- siders the case improbable on the score of smaller dimensions in the former species. Geranoaetus gracilis Miller from the asphalt is the smallest of the fossil eagles from California and, as indi- cated above, this species is about the same size as A. sodalis Shu- feldt. Marsh himself considered the Loup Fork specimen to be "nearly as large as the Golden Eagle," in which case A. dananus may be considered as probably intermediate in size between Aquila chrysaetos (Linnaeus) and Morphnus woodwardi Miller. The only other fossil falconids from American localities out- side of California are Cope's Palaeoborus umbrosus, 29 which Lucas 30 very properly ascribes to the Polyborinae, and two species from South America recorded by the Argentine palaeontologists, Moreno and Mercerat. 31 Lagopterus minutus Mor. and Mer. is the smaller of these two South American species. It is repre- sented by an almost perfect humerus which, according to the authors describing it, is intermediate between Buteo and Poly- borus, with the preponderance of characters relating it with Polyborus. The other species, Foetopterus ambiguus, Mor. and Mer., is considered to be intermediate between Buteo and Cath- artes, but is assigned by the authors to the Falconidae. The 28 Marsh, O. C., Am. Journ. Sci., vol. 2, p. 125, Aug. 1871. 29 Cope, E. D., U. S. Geol. Surv. W. of 100th Merid., vol. 4, pt. 2, p. 287, 1876. sozittel, Textbook of Palaeontology, trans, by Eastman, vol. 2, p. 277, 1902. si Moreno and Mercerat, Palae. Argentina, An. Mus. La Plata, vol. 1, 1891. 1912] Miller: Pacific Coast Avian Palaeontology 95 more intimate relationships of the forms are not discussed by the authors. LIST OF SPECIES ASSIGNED TO THE SUBORDER FALCONES THAT ARE KNOWN TO OCCUR AS FOSSILS IN NORTH AMERICA Species marked with the asterisk are extinct or are no longer repre- sented in the region. Species marked with the double asterisk are con- sidered to show their closest relationship to forms at present more southern in their distribution. Elanus leucurus (Vieillot), Eancho La Brea. Circus hudsonius (Linnaeus), Eancho La Brea, Fossil Lake. **Circus sp. (smaller than hudsonius), Rancho La Brea. Aquila chrysaetos (Linnaeus), Rancho La Brea. *Aquila sodalis Shufeldt, Fossil Lake. *Aquila pliogryps Shufeldt, Fossil Lake. *Aquila dananus Marsh, Loup Fork. Haliaetus leucocephalus (Linnaeus), Rancho La Brea. **Morphnus woodwardi Miller, Rancho La Brea. **Geranoaetus grinnelli Miller, Rancho La Brea. **Geranoaetus melanoleucus Auct. (?), Hawver Cave. **Geranoaetus fragilis Miller, Rancho La Brea. Buteo borealis (Gmelin), Rancho La Brea, Potter Creek Cave. Buteo swainsoni (?) Bonaparte, Samwel Cave. *Buteo, sp. (larger than Archibuteo), Rancho La Brea. Archibuteo ferrugineus (Lichtenstein), Hawver Cave. Falco peregrinus Tunstall, Rancho La Brea, Potter Creek Cave. * Falco, sp. (smaller than peregrinus), Rancho La Brea. Falco sparverius Linnaeus, Rancho La Brea, Samwel Cave and Potter Creek Cave. **Polyborus tharus Auct., Rancho La Brea. *Palaeoborus umbrosus (Cope), Loup Fork of New Mexico. Accipiter velox (Wilson), Samwel Cave. The species of Circus remaining undetermined is a form smaller than the North American C. hudsonius. It is not named in this paper since no opportunity has been presented to com- pare it with the South American species Circus cinereus and C. maculosa. The last two species, it seems, are smaller than C. hudsonius and possibly the asphalt specimens referred to the indeterminate species are of a form identical with the one or the other. The material from Rancho La Brea representing Polyborus is abundant and embraces most parts of the appendicular skele- ton and the beak, including the characteristic nareal region. All this material was compared very carefully with the Recent 96 University of California Publications in Geology [VOL. > phase of Polyborus tharus as represented by a single specimen from Argentina. As no appreciable difference could be noted, the fossil form is referred to the existing species, P. tharus. Anomalies in Distribution. According to Ridgway 32 the present distribution of Polyborus tharus is from Amazonia south- ward through South America. The bird thus reaches in the Argentine and the Patagonian climates a set of conditions as rigorous as any that it would be liable to experience in the northern hemisphere in the latitude of Los Angeles. The ex- tremes of climate due to the presence of the ice sheet is thought by Allen to have given rise to the periodical movements of birds which finally merged into the present seasonal migration. 33 Would not a plausible explanation be that the polyborine under discussion was driven southward by the cold of the glacial epoch but failed to respond to the later amelioration of climate because of a nature less susceptible to the development of a migratory instinct and therefore remained in the lower latitudes or below the tropics? No record of the true Polyborinae is yet found in the deposits of the southern hemisphere to correspond with the Pliocene form, Palaeoborus umbrosus (Cope), from New Mexico or to extend the occurrence of the group even back to the Pleistocene, as the Bancho La Brea material does so abund- antly for the northern hemisphere. If, on this slender thread of negative evidence, we assume that the group arose in the North Temperate zone, the explanation suggested above seems a plausible one. Geranoaetus and Circus present cases similar to that of Poly- borus, while Morphnus differs in that the genus is at present limited to the tropics and probably never reaches a southward distribution which would correspond climatically with the region of Hawver Cave or of Los Angeles. These two cases of Polyborus and Morphnus mentioned above are typical of as many classes of change in distribution since the formation of the various Pleistocene deposits. Parallel with Polyborus there appear the following fossil forms whose nearest 32 Ridgway, R., U. S. Geol. & Geog. Surv. Terr., vol. 1, No. 6, p. 451, 1876. ss Allen, J. A., The geography and distribution of birds, Auk. vol. 10, No. 2, April, 1893. Miller: Pacific Coast Avian Palaeontology 97 relatives occur in the southern hemisphere at a latitude corres- ponding with the region of deposit in the northern hemisphere. Fossil Species Nearest Living Eelative Phoenicopterus copei Shufeldt Phoenicopterus ruber ? Linnaeus Cieonia maltha Miller Euxenura maguari (Temm.) Mycteria americana Linnaeus Mycteria americana Linnaeus Jabiru mycteria (Lichtenstein) Jabiru mycteria author Catharista occidentalis Miller Catharista urubu (Vieillot) Sarcorhamphus clarki Miller Sarcorhamphus gryphus Auct. Circus, sp Circus cenereus or C. maculosus Geranoaetus melanoleucus Auct Geranoaetus melanoleucus Auct. Geranoaetus fragilis Miller Polyborus tharus Auct Polyborus tharus Auct. Cases parallel with Morphnus in having their nearest related Recent phase limited to more tropical zones are as follows : Fossil Species Nearest Living Eelative Pavo californicus Miller Pavo cristatus or Meleagris ocellatus Morphnus woodward! Miller Morphnus guianensis Auct. Geranoaetus grinnelli Miller Morphnus guianensis Auct. Micropallas whitneyi (Cooper) Micropallas whitneyi (Cooper) Geococcyx (?),sp .Neomorpha geoffroyi (Temm.) One of the striking features in the study of so representative a series of deposits, all of so nearly the same age as are the bird-bearing deposits of the Pacific Coast, is the total absence of certain forms which one would expect to find therein. While it is conceded that negative evidence in palaeontology is a frail peg upon which to hang an opinion, yet the negation may be so pronounced and so uniformly persistant that, in some cases at least, the only conclusion possible is that species did not occur in the region during the time of deposition. The particularly favorable conditions offered at Rancho La Brea for the trapping of vultures and eagles has been commented upon in a previous paper on the condors. There was exposed at that place during an indefinite period a more or less con- stantly baited trap which was unusually attractive to both vul- ture and eagle. It was automatic in its operation, effective in its hold upon the victim, and almost ideal in the preservation of its catch, the remains of which were sealed from the air in liquid asphalt while still in the flesh. The entire collection of raptorial remains includes, however, no specimen of the royal vulture (Gyparchus papa) or of the harpy eagle (Thrasaetus harpy a}, 98 University of California Publications in Geology [V L - 7 both of which occur at present along the Mexican border within fifteen degrees of the latitude of Los Angeles. The collection of wading birds from the coast, while not rich in point of numbers, embraces a goodly variety. Jabiru, Myc- teria, Ciconia, Grus, Ardea, and Phoenicopterus are represented ; yet there is no record of the spoonbill (Ajaia) or of the ibis (Guard), both of which have been taken in the flesh well to the northward of Rancho La Brea. Grouse, quail, and meleagrines have been taken in various of the deposits under discussion; yet we find there none of the cracid birds such as Ortalis which occurs at present along the Rio Grande valley of Texas. The absence of the above-mentioned species, particularly the Raptores, from all the bird-bearing deposits thus far known to North America becomes very striking in view of the large num- ber of instances recorded of the southward retraction of species and genera since the Pleistocene period. It is possible that the forms mentioned above were more sensitive to the cold and were driven southward before the deposition of the Pleistocene strata thus far explored, or that they were, on the other hand, more tropical species that have only in Recent time diffused north- ward to their present range. Gyparchus is reported from the Pleistocene caves of Brazil by Winge (op. cit.) which fact would support the latter hypothesis. Polyborus ckeriway would fall in the same category with Gyparchus, being represented in the asphalt by its close relative Polyborus tharus. The same is per- haps true of the Recent species of Geococcyx found in the Son- oran zone of California at the present time but represented in the asphalt only by a longer-shanked form which can scarcely be considered as the direct ancestor of the living Geococcyx cali- fornianus. The species from the asphalt may be identical with one of the species of Neomorpha from South America, comparison between them having been thus far impossible. Approximately eighty species of true columbine birds inhabit the Americas today and many of the species are forms which feed on the ground and which congregate about water holes to drink; yet there is no specimen in all the material examined which is referable to this group. The commonest species in the 1912] Miller: Pacific Coast Avian Palaeontology 99 coast region today is the turtle-dove (Zanaidura macroura), a bird of wide distribution over the Austral region and even to the tropics. Its habits and its abundance are such that one can scarcely concede as possible that it could have been present during the deposition of the Pleistocene beds of Rancho La Brea and yet not be preserved as a fossil. Palamedea and Cariama have in their present home in South America a distribution and habits not unlike those of the stork, Euxenura. Both groups are, however, absent from the fossil collections. The peculiarly isolated positions which these birds occupy in the scheme of classification, as well as the measure of uncertainty as to their proper location systematically, makes any light that palaeontology might throw upon the subject especially desirable. Most careful search was made therefore to see if any part of the skeleton of these birds had been preserved, but nothing was found that resembled either species in the smallest degree. The parrot order, abundant a few degrees to the southward, is unrepresented in the deposits. This may be due to the fact that the only forest fauna which we have preserved to us (cavern deposits) is of Upper Sonoran and lower Transition zones, and thus local conditions may have been unfavorable for these birds. On the other hand, as suggested in the case of Ortalis, they may have been driven southward before the deposition of any of the beds thus far explored. All trace of true struthious birds is lacking in the collec- tions also. The northward diffusion of such forms as the eden- tates and Hydrockoerus among the mammals, the presence since early Pleistocene time of rheas in South America, the occurrence of tridactyl struthionids in the Pliocene of northern India, and" of Struthiolithus in the superficial deposits of northern China, increase the probability that some day the discovery of true struthious birds in North America will be announced. The most potent factors that would bring about such distribution are first, the possible northward diffusion of rheids along with eden- tate mammals and, second, the passage of Struthiolithus or its relatives along the line of proboscidean invasion from Asia by way of the land bridge to Alaska. 100 University of California Publications in Geology [VOL. 7 The earliest occurrence of rheids in South America is in strata now referred to the Pleistocene (the Pampean of Monte Hermosa). If the group had reached that continent by way of the Antarctic at an earlier time, their bones would probably be found with the primitive mammals supposed to have been derived from Australia and known to us from the Santa Cruz beds. The rheas with their true struthious characters could hardly have originated de novo in South America; hence the conclusion that they entered from the north, as did the true cats, deer, elephants and other mammals of northern or Old World origin. Cope's discovery of Diatryma 94 in the Wahsatch Eocene of New Mexico was at first considered as fixing a very early date for the group of Struthiones in the New World. Lucas, 35 how- ever, places this unique specimen in the group of Stereornithes with the great Phororkacos of South America (Miocene of Santa Cruz). A wide gulf exists between the ostriches and these South American phororhacids. The latter are more probably a local development brought out in response to the peculiar con- ditions prevailing there in Tertiary time. There existed in South America no large carnivores among mammals until the northern incursion of machaerodonts and the true felines in relatively late geological time. Edentates were left free to develop to the tremendous extent noticeable in the South American Tertiary and Quaternary. In this region of low pressure among mam- mals there developed unrestrained the predatory bird Phoro- rhacos, to occupy a bionomic place like that of the mammalian carnivore. The reference by Lucas of the North American Dia- tryma to the Stereornithes is tentative. He states the case in these words in part: "Still there are sufficient resemblances be- tween the two to warrant the suggestion that if material comes to light it will be found that the affinities of Diatryma are with the Stereornithes and not with the Dromaeognathae. " In view of the indeterminate character of the single specimen of Diatryma where its relationship between two such distinct 34 Cope. E. D., U. S. Geol. Surv. Terr. W. of 100th Merid., vol. 4, pt. 2, p. 69, 1876. 35 Lucas, F. A., Proc. U. S. Nat. Mus., vol. 24, p. 545, 1903. 1912] Miller: Pacific Coast Avian Palaeontology 101 groups as the Struthiones and the Stereornithes are in question, it would seem that the chief value of Cope's discovery is to show us that a group of gigantic terrestrial birds can inhabit a region and leave almost no trace of their occupation of that part of the globe. The same fact is pointed out by Eastman 30 in his discussion of Struthiolithus and the distribution of the Dromaeognathae. Before the discovery of this species in the superficial deposits in the mountainous regions of northern China no one would have surmised that this great area to the north of India was ever inhabited by struthious birds. Why not expect, then, with perfect propriety, that some day the path of immigration of Rhea into South America may be traced in yet undiscovered deposits of North America ? The other principle which encouraged the search for rheaids in the asphalt, that of a northward migration of southern forms in the Pleistocene, is applicable whether Rhea be considered a product of the southern continent or not. Among mammals we have the northward diffusion of the various edentates and Hydrochoerus, which may be considered products of southern soil, and we have also a re-entrance from the south of certain forms which are Neogaeic by adoption. For example, we may look upon Didelphys as having performed such migration. The objection might be raised that the tropical belt would act as a barrier preventing the plains-dwelling RJiea from retracing its steps, but such an objection is reduced to questionable validity by the presence of true rheids in the cavern deposits of Brazil. The following is a list of lipotypes which are considered by the author as of particular interest: LIST OF LIPOTYPES Gavia, sp. Palamedeidae all species "Gyparchus papa Auct. Cariamidae all forms Thrasaetus harpya Auct. Phororhacidae all species Polyborus cheriway (Jaquin) Gaura, sp. Cracidae all species Plegadis, sp. Columbae all species Ajaia, sp 1 . Psittaci all species Geococcyx calif ornianus (Lesson) 36 Eastman, C. R., Bull. Mus. Comp. Zool. Harvard Coll., vol. 32, p. 127-144, 1898. 102 University of California Publications in Geology [VOL. 7 Possible Influences Conditioning Present Distribution of Cer- tain Groups. In considering the relation of past to present dis- tribution of American birds, at least two principles present them- selves in explanation of the apparent southward retraction of certain forms since Pleistocene time. The first is typified by the case of Polyborus tharus. May this species not have been driven southward across the equator after the time of formation of the asphalt deposits by the advance of a cold period such as sent the mammals of the Ovibos zone as far south as Big Bone Lick and Conard Fissure? Extremes of climate due to the presence of the ice sheet are thought by Allen 37 to have given rise to the periodical move- ments of birds which finally merged into the present seasonal migration. The polyborine under discussion may thus have been driven southward, but lacked the incipient migratory instinct and furthermore failed to return northward upon the amelioration of the climate. This failure may have been due to the presence of more virile species blocking the return path, or it may have been due to the limiting tendency of the torrid zone which it would have had to recross in a return to the north. No record of the true Polyborinae has yet been found in the deposits of the southern hemisphere to correspond with the Pliocene Palaeo- borus of New Mexico or to extend the occurrence of the group even back to the Pleistocene, as the Eancho La Brea material does so abundantly for the northern hemisphere. If, on this slender thread of negative evidence, we assume that the group arose in the North Temperate Zone, the explanation suggested above seems a plausible one. The distribution of Circus, Geran- oaetus, Sarcorhamphus, and Euxenura would further uphold this view of the question. These birds are typically of the southern hemisphere in latitudes to the south of the tropics or at high elevations and the Tierra Caliente would act as a more or less effective barrier to their northward dissemination. The second hypothesis offered is that the returning annual isotherm has never yet reached the point at which it stood during the deposition of the fossil remains. Sinclair (Op. cit., p. 19) links the Potter Creek Cave deposits pretty closely with the 37 Allen, J. A., The Auk, vol. X, No. 2, Apr. 1893. 1912] Miller: Pacific Coast Avian Palaeontology 103 Upper San Pedro series of marine deposits and the San Pablo Bay oyster beds at Rodeo. These shell deposits are considered by western palaeontologists to represent a time of higher average annual temperatures than prevail in the region at present. The cases of Morphnus, Micropallas, Geococcyx (') and Pavo make a strong aggregate in favor of this theory. To harmonize the cases of Circus, Polyborus, Sarcorhamphus, Geranoaetus and Ciconia with those of the more tropical species, it would be neces- sary to assume nothing further than that these forms, since the partial amelioration of the climate, had developed powers of resistance to cold and had extended their ranges to the southward instead of remaining intertropical species. The extension of range took place from the tropics southward instead of to the northward again because of overcrowded conditions in the north. The advance of arctic cold toward the equator would drive north- ern animals into narrower and narrower quarters, while the forms of the southern hemisphere, under like encroachment of the antarctic, would experience the opposite effect. The conver- gence of all the Boreal species into the Austral on the continent of North America would be in effect like crowding the basal con- tents of a cone into its apex. The result would be an enormous intensification of the natural attrition of species upon species with a resultant stimulus to the surviving form. In the southern hemisphere conditions would be reversed and the advance of polar cold, whether synchronous with or alternating with the northern fluctuations, would have much less serious effect. As- suming the various faunal zones to be fully populated, the driv- ing of the Patagonian fauna into the wide expanse of Argentina and southern Brazil would serve to dilute greatly the Boreal fauna without materially disturbing the Austral. A form that had been obliged to flee the rigorous conditions resulting from an advance of the cold in North America might find, upon the return of milder conditions, that the path of least resistance to expanding range from the tropics led toward the south. Bird Remains as Indicators of Climatic Conditions. Certain appearances in the deposits at Rancho La Brea might be inter- preted as evidence that the climate during deposition of the beds was warmer and more moist than it is at present in the region. 104 University of California Publications in Geology [Vo L - 7 The fauna is certainly a rich one and embraces a considerable variety of ungulates of large size which were dependent on a goodly supply of grass and browse. Purely local conditions of dainage may, however, have brought about such a condition. In the fickle streams of the southwest such change of bed may occur in a single season and a deposit laid down under conditions of abundant moisture amounting almost to a peat formation may be left high and dry after a severe freshet to suffer a reversion to almost desert condition. Relatively few of the anserines are found in the collections from the asphalt. Geese of the Recent species become almost upland forms during the rainy season when grass is abundant. Euxenura is, according to Hudson's account in Naturalist in La Plata, a plains-dwelling form of the open pampa at some times of the year. The sand-hill crane, Grus canadensis, is notably a plains feeder in the winter and spring, while the great blue heron, Ardea herodias, has been seen by the author on the dry hillsides in midsummer seemingly in pursuit of grasshoppers. The presence of these birds in the asphalt in the limited numbers found is not then a positive indication of open water or of even marshy ground. The water- worn fragments of wood and the leaves in bedded deposit are such as occur in small steams of the region today when the streams may be more or less intermittant. A rich and varied mammalian fauna is taken by some writers as an indication of mild climatic conditions. Such conclusion seems scarcely war- ranted, however, in view of the present conditions in the desert parts of the world. The writer found deer abundant on the open and thorny desert of Lower California in the region of Cape San Lucas. On the mainland of Mexico, in the desert of Sonora, deer, peccary, and mountain sheep are abundant. The accounts by Roosevelt of game distribution in Africa indicate an abundance and a great variety of game in almost desert regions of that continent. On the Mohave, the Colorado, and the great Nevada deserts, the most ephemeral pools of water, even when highly impregnated with alkaline salts, are the resort of multitudes of waterfowl, while Cope and Shufeldt describe abundant life in the region near Fossil Lake on the Oregon Desert. 1912 J Miller: Pacific Coast Avian Palaeontology 105 There is some very credible evidence that the mammals en- trapped in the asphalt pools were in part attracted to the locality by water. Over the top of the asphalt layer there may accumu- late after a shower a stratum of fairly pure rain water, so little does the viscid asphalt mix with the water. Such an accumula- tion remains in the impervious basins until evaporated by the heat of the sun, without loss by seepage through the oil-impreg- nated earth. Pools of water suitable for the use of cattle and horses thus remain impounded in natural reservoirs after adja- cent streams have vanished. Natural reservoirs are of such im- portance in the southwestern deserts as to have received the local Spanish name of "tinajas," and wild mammals of the desert come from long distances to drink at them. Such conditions would tend to concentrate the remains of mammals of a poorly watered region and furnish the asphalt trap with scores of victims which otherwise would have escaped. 38 Summing up the evidence of a warm, moist climate during the Pleistocene, we have the following points, all of which are inconclusive : 1. The presence of species whose nearest relatives are at present more tropical in distribution. 2. The presence of an abundant fauna which is suggestive of favorable conditions of climate. 3. The presence of aquatic species and of waterworn chips laid down in places now dry but showing no great changes in topography. 4. The suggestion that the mammals of Rancho La Brea were in some measure led to the region by the presence of water. Time Relations as Suggested by a Study of Bird Remains. Osborn divides the Pleistocene period into three great time subdivisions, namely, Pre-Glacial, Glacial- and Post-Glacial. 39 The Glacial again shows evidence of division into five periods of fluctuation, during which the ice cap oscillated northward and southward with the changing isotherms. The period also represents a time of high elevation of the land surface in general ss See Darwin, C., Journal of Voyage of H.M.S. Beagle, 1845 (New ed. 1909), pp. 128-130. so Osborn, H. F., The Age of Mammals. New York, 1910. 106 University of California Publications in Geology [V L - 7 as compared with the Pre-Glacial. The Post-glacial epoch was characterized by an ameliorated climate and a depression of the land surface. Great river floods and large lakes were the result of this amelioration, and extensive fluviatile and lacustrine de- posits appear, while the previously restricted species of verte- brates spread out over parts of the country that were formerly covered by the ice cap. The faunas of the time are divided by Osborn into three life- zones which are distributed through the Pleistocene, but do not coincide with the three time divisions as given above. They do not necessarily represent consecutive faunas, but rather faunas from different topographic divisions which, in some respects, overlap each other, though in the main consecutive. Charac- teristic mammals have given the names to these zones as follows : Equus Zone, a plains fauna partly earlier than and partly synchronous with the second, the Megalonyx Zone, which was a forest and meadow fauna mainly of mid-Pleistocene time. The third, or Ovibos Zone, is an impoverished fauna, perhaps cor- responding with the Arctic and Tundra period of Europe and synchronous with the last great glacial advance, the period of maximum glaciation, which is recorded in the great terminal moraine. RELATIONS OF SEVERAL PLEISTOCENE MAMMALIAN HORIZONS; ADAPTED FROM OSBORN Equus Zone Megalonyx Zone 6 Kansas Pleistocene, several 9 Big Bone Lick, Ken. localities. 8 Samwel Cave, Calif. 5 Lake Lahontan, Nev. 7 Potter Creek Cave, Calif. 4 Fossil Lake, Ore. 6 Washtucna Lake, Wash. 3 Eock Creek, Texas. 5 Rancho La Brea, Calif. 2 Hay Springs, Neb. 4 Ashley Eiver, S. Carolina. 1 Peace Creek, Fla., Late Plio- 3 Frankstown Cave, Penn. cene or Early Pleistocene. 2 Port Kennedy Cave, Penn. 1 Afton Junction, Iowa. 1st in- terglacial stage. Ovibos Zone 4 -Alaska Ground Ice. 3 Conard Fissure, Ark. 2 Scattered middle west. 1 Big Bone Lick, Ken. 1912] Miller: Pacific Coast Avian Palaeontology 107 The exact time-relations between the several faunas is not determinate, and the overlap of one column upon another is purposely indefinite. The Equus fauna is considered in part older than the Megalonyx fauna and this in turn than the Ovibos. It must be stated also that the study of mammalian remains from Rancho La Brea, from the caves of California, and from Fossil Lake, Oregon, is still being actively pursued and the list of species revised. Any statement of time-relations must be considered as purely tentative. Few investigators have had so wide and so comprehensive an acquaintance with the mammalian palaeontology of North America as has Professor Osborn; hence it is considered in this connection that his chronological arrange- ment of the various mammal-bearing horizons represent the truth as nearly as we have yet arrived at it. It will be noted that the Fossil Lake horizon is placed by him midway in the tabulation of the Equus Zone fauna while Rancho La Brea and the caves occupy the middle and upper parts of the Megalonyx Zone. Thus Fossil Lake is to be con- sidered as the earliest Pleistocene horizon on the coast produc- tive of avian remains. If we apply the criterion of percentage of extinct forms, the evidence furnished by the avian remains would indicate a different time-relation than that suggested by Professor Os- born. The various horizons here discussed show the following sequence when arranged according to the percentage of Recent species of birds recorded fossil: Eancho La Brea 60% still living Fossil Lake 66% still living Potter Creek Cave 68% still living Samwcl Cave 72% still living Hawver Cave 79% still living The application of this principle in the case of fossil birds seems, however, less accurate than in the case of mammals when we consider the migratory nature of many bird species. The Fossil Lake fauna according to this basis of estimate would appear to be younger than that of Rancho La Brea. A glance at the list of species from Fossil Lake shows, however, the large 108 University of California Publications in Geology [VOL. 7 percentage of migratory forms such as the anserines and the pygopodes. These birds by their migratory habits are rendered largely immnne to the effects of climatic change that might have brought about extinction in such forms as the raptors and the scratchers. Ten of the fifteen extinct species recorded from Fossil Lake belong to genera which are at present non-migratory in the region. Whether or not these genera were migratory during Pleisto- cene time is, of course, a matter of pure conjecture. Allen 40 suggests that it was during the Glacial Epoch that the migratory instinct was indelibly impressed upon birds by the pronounced seasonal contrast prevailing at that time. Whether the instinct was at that time incipient or real, it seems proper to conclude that those genera which now display it are the ones which would have profited by its initial operation and have escaped extinction. There presents itself, then, the very potent suggestion that the relatively small proportion of extinct forms represented in the Fossil Lake horizon is due to the fact that many of the genera there represented possessed or else developed the migra- tory instinct and were preserved except as influenced by other factors. The remaining four horizons may more properly be com- pared as to age upon the basis of percentage of surviving species, and such comparison bears out the conclusions reached by Os- born in his study of the mammals. Causes of Extinction of Birds. After a consideration of the varied and in many respects remarkable avifauna of Pleistocene times, it is natural that the causes of extinction of these forms should hold an important place in our attention. Why should we now have but two eagles in southern California where five once flourished? Why does but one condor remain of the five species found fossil ? The large phase of the variable Pleistocene Haliaetus has withdrawn toward the north into British Col- umbia and Alaska, while Phoenicopterus, the ciconids, Polyborus and the morphnine eagles have withdrawn to the southward. The gigantic Teratornis disappeared, leaving no near relative 40 Allen, J. A., The geography and distribution of birds, Auk, vol. 10, No. 2, Apr. 1893. 1912] Miller: Pacific Coast Avian Palaeontology 109 to represent the family among the Catharti formes. How late did this great bird persist, and did that important factor, man, have anything to do with his disappearance? According to Dr. C. Hart Merriam, 41 the Me-wah Indians of California have a legend concerning a gigantic vulture, Yel-lo-kin, so large that he was able to capture the condor and carry him up through a hole in the sky. The bird myths of these Indians indicate a close acquaintance with the California species. It may be that Tera- tornis persisted until the arrival of man upon the scene, and thus gave rise to the Mew-wah Indian myth of Yel-lo-kin. Granting the possible truth of such an assumption as the con- temporaneity of man and Teratornis, the primitive human animal could have had but little cause to direct his efforts against the large raptorial birds. His meagre offensive armament would probably have availed him but little in any event. Thus the only influence he would have been likely to exert would be but the indirect effect through the extermination of large mammals. The possibility of man's having exerted any such influence on the lives of avian species seems remote, in view of the negative evidence afforded by the absence thus far of human remains from western horizons of undoubted Pleistocene age. Direct extermination, or the sharpening of competition, by incursions of Old World forms, is a theory without the support of any tangible evidence in the case of birds. The procyonids and Didelphys are of long standing in America. Felines would greatly influence the larger birds by direct attack either upon the bird or its nest. It seems highly improbable, then, that birds could have been directly influenced by man or the other mammals, but that the chief relation of mammals to the large birds was in the dependence of the latter upon the former for food-supply. As has been pointed out in an earlier paper, 42 the large rap- torial birds depended in a dual respect upon the large mammals. First, these birds fed upon the bodies of either carnivores or herbivores dying of whatever cause ; second, the vulture fed upon the rejected portion of the carnivore's kill. Thus, any factor 41 Merriam, C. H., The Dawn of the World, p. 163, 1910. 42 Miller, L. H., Univ. Calif. Publ., Bull. Dept. Geol., vol. 6, p. 2, 1910. 110 University of California Publications in Geology [ VoL - 7 which tended to reduce the numbers of either group of mam- mals must have reacted also upon the large birds of prey. It is not at all improbable that the things which brought about the extinction of Pleistocene mammals were also directly operative in bringing about the extinction of many species of birds. Non-raptorial birds, except where migratory, would re- spond to climatic changes very much as did mammals. Osborn makes suggestions regarding the mammals as follows: ' ' the Glacial period in North America originated certain new con- ditions of life which directly or indirectly resulted in extinction. "These conditions include diminished herds, enforced migrations, the possible overcrowding of certain southerly areas, changed conditions of feeding, disturbance in the period of mating and reproduction, new rela- tions with various enemies, aridity, deforestation; in short, a host of indirect causes. ' ' 43 Disease, in all probability a factor in the extinction of some mammals, may likewise have been the determining influence in the case of certain birds. During the winter of 1908-9 in south- ern California, the bodies of thousands of sea-birds were cast up on the beach within a comparatively short time. Many of these specimens were examined by Dr. F. C. Clark of Los An- geles and by the author. The intestines were found filled with tape-worms. Mildness of the weather coupled with the profound emaciation of the birds indicated that death was not due to violence or sudden cause. While the presence of parasites may not have been the only influence leading to death, it was, in all probability, an important and possibly the determining factor. If, as is so variously suggested, the rainfall is now much less than it was during the Pleistocene, the influence upon bird life may have been effective over wide areas through the several factors of food, shelter and nesting sites. Pavo and Meleagris, although not always confined to wooded country, are both forms which might have been strongly influenced by deforestation. The morphnine eagles, with the possible exception of Geranoae- tus, are forest-dwelling birds. The local extinction of these birds in California may have resulted from a thinning-out of the forests. 43 Qsborn, H. F., The Age of Mammals (New York, Macmillan, 1910). 1912] Miller: Pacific Coast Avian Palaeontology 111 Development of gigantic size in the cathartids is in effect a case of over-specialization in that it works frequently to the detriment of the species. The condors of today are of such unwieldy size that, after a full meal, they experience much diffi- culty in taking wing from low ground. This fact is reported to have caused the destruction of many individuals which had been led to alight in places from which they could not rise again into the air. Teratornis must have attained a bulk almost thrice that of the condor if we may judge from coracoid and furcula. The suggestion conveyed by the sternum is that the pectoral muscles were not so heavy in proportion, yet the weight of the bird must have been far greater than that of the condors. The nature of its food was such that it must have come to the ground to feed. The effort to rise again, gorged with food, must have been a severe tax upon its strength, and slowness in taking wing may have subjected it to frequent danger. The high, compressed beak of Teratornis resembling the eagle's in form, though struc- turally cathartine, indicated the extreme of specialization. The large body size, likewise a phase of specialization, may have mili- tated in the end against the life of the species. The principle of specific decay or senility of species as a cause of extinction may have suffered somewhat through the too frequent application of it by the palaeontologist, yet there often appear cases in which no other factor seems adequate to explain the loss of a species. Certainly the intersterility of species would lead to inbreeding with its attendant ill effects. Incipient strains of intersterility within a species might, where geographically restricted, lead to the more rapid deterioration of the stock; generation upon generation of individuals, like the succeeding generations of somatic cells, become less and less virile until the species would decline in a manner comparable to the senile decay of the individual. The rapid decline of certain of the less con- spicuous species of Hawaiian birds, such as Palmeria and Chae- toptila, seems almost of necessity the result of such depleting influence. How effective this factor was in robbing us of many Pleistocene birds it is of course impossible to estimate; it would seem proper, however, to look upon it as possibly a contributing cause. 112 University of California Publications in Geology [VOL. 7 TABULAR ARRANGEMENT OF WEST-AMERICAN PLEISTOCENE AVIFAUNAS ^Echmophorus lucasi Miller ............................................ * ^chmorphorus occidentalis (Lawrence ........................ Colymbus holboelli (Eeinhardt) ........................................ * Colymbus auritus Linnaeus .............................................. * Colybus nigricollis californicus (Heermann) .............. * Podilymbus podiceps (Linnaeus) .................................. * Larus argentatus Pontoppidan ...................................... * Larus robustus Shufeldt .................................................. * Larus californicus Lawrence ............................................ * Larus oregonus Shufeldt ................................................ * Larus Philadelphia (Ord) ................................................ * Xema sabini (J. Sabine) ................................................ * Sterna elegans Gambel .................................................... * Sterna forsteri Nuttall .................................................... * Hydrochelidon nigra surinamensis (Gmelin) ................ * Phalacrocorax macropus (Cope) ........................ ............ Pelecanus erythrorhynchos Gmelin ................................ * Lophodytes cucullatus (Linnaeus) .................................. * Anas platyrhynchos Linnaeus ............... . .......................... Chaulelasmus streperus (Linnaeus) .............. -. ................. * Mareca americana (Gmelin) ............................................ Nettion carolinense (Gmelin) .......................................... * Querquedula discors (Linnaeus) .................................... * Querquedula cyanoptera (Vieillot) ................................ Spatula clypeata (Linnaeus) .......................................... * Dafila acuta (Linnaeus) .................................................. Aix sponsa (Linnaeus) ...................................................... Marila valisineria (Wilson) ............................................ * Clangula islandica (Gmelin) .......................................... Harelda hyemalis (Linnaeus) ............................. . ............ * Erismatura jamaicensis (Gmelin) .................................. Anser condoni Shufeldt .................................................. * Anser albifrons gambeli Hartlaub .................................. ? Branta hypsibata (Cope) ................................................ Branta canadensis (Linnaeus) ...................................... Branta propinqua Shufeldt ............................................ * Chen hyperboreus (Pallas) ............................................ Olor paloregonus (Cope) .................................................. * Indeterminate anserine .................................................... Indeterminate anserine .. 1912] Miller: Pacific Coast Avian Palaeontology 113 fS -M fc C .73 o o> ? r ca c S IJ2 1 jS Pi H M. OR fM Indeterminate anserine Phoenicopterus copei Shufeldt * Ciconia maltha Miller Jabiru mycteria (Lichtenstein) Mycteria americana Linnaeus Ardea herodias Linnaeus Ardea paloccidentalis Shufeldt * Grus minor Miller Grus canadensis (Linnaeus) Fulica americana Gmelin Fulica minor Shufeldt * Lobipes lobatus (Linnaeus) * Oreortyx picta (Douglas) Lophortyx californica (Shaw) Lophortyx, sp Dendragapus obscurus (Say) Bonasa umbellus (Linnaeus) .'. Tympanuchus pallidicinctus (Eidgway) * Pedioecetes phasianellus columbianus (Ord) * Pedioecetes lucasi Shufeldt * Pedioecetes nanus Shufeldt Palaeotetrix gilli Shufeldt * Indeterminate odontophorid Meleagris, sp Pavo californicus Miller Gymnogyps californianus (Shaw) 7 ... Gymnogyps amplus Miller Sarcorhamphus clarki Miller Cathartornis gracilis Miller Pleistogyps rex Miller Cathartes aura (Linnaeus) Catharista occidentalis Miller Catharista shastensis Miller Teratornis merriami Miller Elanus leucurus (Vieillot) Circus hudsonius (Linnaeus) Circus, sp Accipiter velox (Wilson) Buteo borealis (Gmelin) Buteo swainsoni Bonaparte (?) Buteo, sp - Archibuteo ferrugineus (Lichtenstein) Aquila chrysaetos (Linnaeus) -~. 114 University of California Publications in Geology [VOL. 7 3 J I 5 I * 1 fill fa Pi P-i 02 Aquila pliogryps Shufeldt * Aquila sodalis Shufeldt * Haliaetus leucocephalus (Linnaeus) Morphnus woodwardi Miller * Geranoaetus melanoleucus Auct. (?) Geranoaetus grinnelli Miller * Geranoaetus fragilis Miller * Falco peregrinus Tunstall Falco, sp * Falco sparverius Linnaeus Polyborus tharus Auct * Aluco pratincola (Bonaparte) Asio wilsonianus (Lesson) Asio flammeus (Pontoppidan) Otus asio (Linnaeus) Bubo virginianus (Gmelin) Bubo sinclairi Miller * * Speotyto cunicularia hypogaea (Bonaparte) Glaucidium gnoma Wagler Micropallas whitneyi (J. G. Cooper) Neomorpha ?, sp Colaptes cafer (Gmelin) Otocoris alpestris (Linnaeus) Cyanocitta stelleri (Gmelin) Corvus corax Linnaeus Corvus brachyrhynchos Brehm Corvus annectens Shufeldt * Corvus, sp Xanthocephalus xanthocephalus (Bonaparte) Agelaius gubernator (Wagler) Sturnella neglecta Audubon Euphagus cyanocephalus (Wagler) Euphagus affinis Shufeldt * Pipilo, sp Lanius ludovicianus Linnaeus ... * 1912] Miller: Pacific Coast Avian Palaeontology 115 BIBLIOGRAPHY OF PACIFIC COAST FOSSIL/ AVIFAUNAS 1878. Cope, E. D., Bull. U. S. Geol. Surv. Terr, iv no. 2, May 3, 1878. Describes three species of birds from Fossil Lake, Ore. 1892. Shufeldt, E. W., A Study of the Fossil Avifauna of the Equus Beds of the Oregon Desert, Journ. Acad. Nat. Sci. Phila. no. 9, p. 389. 1894. Cope, E. D., On Cyphornis, an Extinct Genus of Birds, Journ. Acad. Nat. Sci. Phila. no. 9, p. 449. 1901. Lucas, F. A., A. Flightless Auk, Mancalla californiensis, from the Miocene of California, Proc. U. S. -Nat. Mus v vol. 24; p. 133. 1909. Miller, L. H., Pavo californicus, a Fossil Peacock from the Quater- nary Asphalt Beds of Eancho La Bre^ Univ. Calif. Publ., Bull. Dept. Geol., vol. 5, p. 285. 1909. Miller, L. H., Teratornis, a New Avian Genus from Eancho La Brea, Univ. Calif. Publ. Bull. Dept. Geol., vol. 5, p. 305. 1910. Miller, L. H., Wading Birds from the Quaternary Asphalt of Eancho La Brea, Univ. Calif. Publ. Bull. Dept. Geol., vol. 5, p. 437. 1910. Miller, L. H., The Condor-like Vultures of Eancho La Brea, Univ. Calif. Publ. Bull. Dept. Geol., vol. 6, p. 1. 1911. Miller, L. H., Additions to the Avifauna of the Pleistocene Deposits at Fossil Lake, Oregon, Univ. Calif. Publ. Bull. Dept. Geol., vol. 6, p. 79. 1911. Miller, L. H., A Series of Eagle Tarsi from the Pleistocene of Eancho La Brea, Univ. Calif. Publ. Bull. Dept. Geol., vol. 6, p. 305. 1911. Miller, L. H., Avifauna of the Pleistocene Cave Deposits of Cali- fornia, Univ. Calif. Publ., Bull. Dept. Geol., vol. 6, p. 385. NOTE. Since the text of this paper went to press, bird remains have been found in the Upper San Pedro Pleistocene at San Pedro, Cal., by Dr. F. C. Clark of Los Angeles. These remains were very generously presented to the present writer by Dr. Clark, and by permission of the latter, were deposited in the Vertebrate Palaeontology Collections at the University of California. Three of the specimens are almost perfect, the several others are too fragmentary for determination. One specimen repre- sents an undescribed species of grebe of the genus ^chmophorus but in view of the fact that the active exploration of these beds now going on will possibly bring to light other remains of like nature, a description of the species is thought unwise at present. Eemains of Bison, Equus, a camelid, rodents, seals, small turtles, and sting rays have also been taken from these beds by Dr. Clark and the writer. * LIST OF SPECIES FROM UPPER SAN PEDRO Mammals Birds Equus ^chmophorus, n. sp. Bison Nettion carolinense (Gmelin) Camelid Sturnella neglecta Audubon VOLUME 4. PBICK 1. The Geology of the Upper Region of the Main Walker River. Nevada, by Dwight Smith I..; .".... aoc Primitive Ichthyosaurian Limb from the Middle Triassic of Nevada, by John Merriam ." lOc 3. Geological Section of the Coast Ranges North of the Bay of San Francisco, by V. C. Osmont 40c 4. Areas of the California Neocene, by Vance C. Osmont. .r loc ntribution to the Palaeontology of the Martinez Group, by Charles E. Weaver ; w or Imperfectly Known Rodents and Ungulates from the John Day Series, by William J. Sinclair .'.. 2oe ". Xew Mammalia from the Quaternary Caves of California, by William J. Sinclair 25c 8. Preptoceras. a New Ungulate from the Samwel Cave. California, by Eustace L. Furlong lOc 9. A New Sabre-tooth from California, by John C. Merriam . 5c 10. The Structure and Genesis of the Comstoek Lode, by John A. Reid 15c 11. The Differential Thermal Conductivities of Certain Schists, by Paul Thelen.. etch of the Geology of Mineral King. California, by A. Knopf and P. Thelen 35c 13. Cold Water Belt Along the West Coast of the United States, by Ruliff S. Holway 14. The Copper Deposits of the Robinson Mining I Nevada, by Andrew C. Lawson 50c 15. I. Contribution to the Classification of the Amphiboles. II. On Some Glaucophane Schists, Syen. by G. Murgoo. 35c 16. The Geomorphic Features of the Middle Kern, by Andrew C. Lawson.... . loc res on the Foothill Copper Belt of the Sierra Nevada, by A. Knopf. 18. An Alteration of Coast Range Serpentine, by A. Knopf. 17 and 18 in one cover loc 19. The Geomorphogeny of the Tehachapi Valley System, by Andrew C. Law- 35c VOLUME 1. Carnivora from the Tertiary Formations of the John Day Region, by John C. Merriam 60c me Edentate-like Remains from the Maseall Beds of Oregon, by William J. Sinclair. Mollusca from the John Day and Maseall Beds of Oregon, by Robert E. C. Stearns. "2 and 3 in one cov loc rstraciont Teeth from the West American Tria- Ina M. Wemple lOc 5. Preliminary Note on a New Marine Reptile from the Middle Triassie of Nevada, by John C. Merriam 10c .tes on Lawsonite, X^olumbite, Beryl, Barite. and Calcite. by Arthur S. Ea'.de lOc California, with Supplemer :s on Other Species of David Starr Jordan 5 ^c 8. Fish Remains from the Marine Lower Triassic of Aspen Ridge. Idaho, by Malcoln. Goddard 5c 9. Benito!- difornia Gem Mineral, by George Davis Louderback. with Chemical Analysis by Walter C. Blasdale oc .tes on Quaternary Felidae from California, by John F. Bovard 11. Tertiary Faunas of the John Day Region, by John C. Merriam and William J. iopods and Insects of California, by Fordyce Grinnell, Jr lOc 13. Notes on the >f the Thalattosaurian Genus Xectosaurus. by John C. Merriam _ >tes on Some California Mineral- hur S. Eakle loc tes on a Collection of Fossil Mammals from Virgin Valley, Nevada, by James Williams Gidley 16. Stratigraphy and Palaeontology of the San Pablo Formation in Middle California. by Charles E. Weaver -w Echinoids from the Tertiary of California, by Charles E. Weaver oc on Echinoids from the Tertiary of California, by R. W. Pack 19. Pavo californicus. a Fossil Peacock from the Quaternary Asphalt Beds of Rancho La Brea. by Lcye Holmes Miller VOLUME 5 (Continued}. PRICE 20. The Skull and Dentition of an Extinct Cat closely allied to Felis atrox Leidy, by John C. Merriam 15 C 21. Teratornis, a New Avian Genus, from Raneho La Brea, by Loye Holmes Miller lOc 22. The Occurrence of Strepsicerine Antelopes in the Tertiary of Northwestern Nevada, by John C. Merriam k 10c 23. .Benitoite, Its Paragenesis and Mode of Occurrence, by George Davis Louderbaek, with chemical analyses by Walter C. Blasdale 75c 24. The Skull and Dentition of a Primitive Ichthyosaurian from the Middle Triassic, by John C. Merriam 10c 25. New Mammalia from Raneho La Brea, by John C. Merriam 5c 26. An Aplodont Rodent from the Tertiary of Nevada, by Eustace L. Furlong lOc 27. Evesthes jordani, a Primitive Flounder from the Miocene of California, by James Zacchaeus Gilbert 15c 28. The Probable Tertiary Land Connection between Asia and North America, by Adolph Knopf lOc 20. Rodent Fauna of the Late Tertiary Beds at Virgin Valley and Thousand Creek, Nevada, by Louise Kellogg 15c 30. Wading Birds from the Quaternary Asphalt Beds of Raneho La Brea, by Loye Holmes Miller , lOc VOLUME 6. 1. The Condor-like Vultures of Raneho La Brea, by Loye Holmes Miller 15o 2. Tertiary Mammal Beds of Virgin Valley and Thousand Creek in Northwestern Nevada, by John C. Merriam. Part I. Geologic History 50c 3. The Geology of the Sargent Oil Field, by William F. Jones 25c 4. Additions to the Avifauna of the Pleistocene Deposits at Fossil Lake, Oregon, by Loye Holmes Miller lOc 5. The Geomorphogeny of the Sierra Nevada Northeast of Lake Tahoe, by John A. Reid 60c 6. Note on a Gigantic Bear from the Pleistocene of Raneho La Brea, by John C. Merriam. 7. A Collection of Mammalian Remains from Tertiary Beds on the Mohave Desert, by John C. Merriam. Nos. 6 and 7 in one cover lOc 8. The Stratigraphic and Faunal Relations of the Martinez Formation to the Chico and Tejon North of Mount Diablo, by Roy E. Dickerson 5c 9. Neocolemanite, a Variety of Colemanite, and Howlite from Lang, Los Angeles County, California, by Arthur S. Eakle lOc 10. A New Antelop" from the Pleistocene of Raneho La Brea, by Walter P. Taylor 5c 11. Tertiary Mammal Beds of Virgin Valley and Thousand Creek in Northwestern Nevada, by John C. Merriam. Part IL Vertebrate Faunas $1.00 12. A Series of Eagle Tarsi from the Pleistocene of Raneho La Brea, by Loye Holmes Miller lOc 13. Notes .on the Relationships of the Marine Saurian Fauna Described from the Triassic of Spitzbergen by Wiman, by John C. Merriam. 14. Notes on the Dentition of Omphalosaurus, by John C. Merriam and Harold C. Bryant. Nos. 13 and 14 in one cover - 15c 15. Notes on the Later Cenozoic History of the Mohave Desert Region in Southeastern California, by Charles Laurence Baker 50c 16. Avifauna t)f the Pleistocene Cave Deposits of California, by Loye Holmes Miller 15c 17. A Fossil Beaver from the Kettleman Hills, California, by Louise Kellogg 5c 18. Notes on the Genus Desmostylus of Marsh, by John C. Merriam lOc 19. The Elastic-Rebound Theory of Earthquakes, by Harry Fielding Reid 25c VOLUME 7. 1. The Minerals of Tonopah, Nevada, by Arthur S. Eakle 25c 2. Pseudostratification in Santa Barbara County, California, by George Davis Louder- back 20c 3. Recent Discoveries of Carnivora in the Pleistocene of Raneho La Brea, by John C. Merriam 5 4. The Neocene Section at Kirker Pass on the North Side of Mount Diablo, by Bruce L. Clark 15c 5. Contributions to Avian Palaeontology from the Pacific Coast of North America, by Loye Holmes Miller 60c NON-CIRCULATING BOOK 244558 UNIVERS 10m-l,'28 ftARY