Birds of the Islands Off the Coast of Southern California
Total Page:16
File Type:pdf, Size:1020Kb
COOPER ORNITHOLOGICAL CLUB PACIFIC COAST AVIFAUNA NUMBER 12 BIRDS OF THE ISLANDS OFF THE COAST OF SOUTHERN CALIFORNIA BY ALFRED BRAZIER HOWELL HOLLYWOOD, CALIFORNIA PUBLISHED BY THE CLUB June 30. 1917 Edited by JOSEPH GRINNELI. and HARRY S. SWARTH at the Mrlsemz of Vertebrate Zoology Lkiversity of Calijh-&a NOTE Pecn:~rc:COMT AVJF_IVN_INo. 12 is the twelfth in a series of publications issued by the Cooper Ornithological Club for the accommodation of paper.3 whose length prohibits their appearance in TIIE CONDOR. The publications of the Cooper Ornithological Club consist of two series-- ls~,‘ ’ CONDOR, which is the bi-monthly organ, and the PACIDVCCOMT AVIFAUKL . For inFormation as to either of the above series, address one of the Club Business Managers, J. Eugene Law, Hollywood, California, or W. Lee Cham- bers, Eagle Rock, California. CONTENTS Introduction .....................................................................................................................................................................5 Acknowledgments ......................................................................................................................................................7 Map of the Islands ......................................................................._........................................................................... 8 Descriptions of the Islands ....................................................................................................._........................ 9 Problems Presented by the Island Avifauna .................................................................................... 13 General Accounts of the Birds .....................................................................................................................17 Hypothetical List ............................................................................................................................._........................ 102 Tabulation of Spe,cies by Islands ...............................................................................................................104 Tabulation of Species by Manner of Occurrence ........................................................................109 Bibliography .....................................................................................................................................................................112 Index .......................................................................................................................................................................................121 INTRODUCTION The need for a publication of some kind embracing all possible information in regard to the avifauna of the islands off the coast of southern California first came to my attention in 1908. At that time I began compiling lists of the birds of each of the islands, for my own use only; but, at the suggestion of a few friends, I began four years ago to get these notes into shape for publication. This was undertaken, not because I have worked the islands more thoroughly than anyone else, which is not the ca.se,but because of the special interest I have in the region. The present contribution was completed and delivered to the Editors in October, 1915, but for various reasons the Club has been long delayed in its pub- lication. During this delay, I have taken the opportunity of bringing the paper up to date, with the beginning of 1917. The territory covered in the present paper consists of the Santa Barbara Islands as properly restricted: Anacapa. Santa Cruz, Santa Rosa and San i\lig- uel, with certain outlying rocks; the more southern group, popularly included under the same general term: Santa Barbara, San Nicolas, Santa Catalina, and San Clemente; and Los Coronados Islands. The last mentioned group does not lie off the coast of southern California, being Mexican territory and pertaining to Lower California, but is included in this report because of location nearby, and because of fauna1 similarity to the other islands named. I regret that I have been unable to spend more time myself in field work- some weeks, at least, on each island. There seems no prospect of this in the near future. and further delay of publication for this reason seems unwise. As a. matter of fact, there has been comparatively little work done upon these islands by anybody, and a visit of several weeks to any one of them is almost sure to add one or more new migrants or winter visitants to t,he list. The scope of this paper, as originally planned for my own use, has necessar- ily been amplified. I have endeavored to cite every publication relating to the island avifauna that could be deemed of import,ance, and to gather all unpub- lished notes relating to the subject, though I suppose it is useless to hope that I have uncovered every one of either. As a matter of general convenience, the nomenclature and order of the third edition of the American Ornithologists ’ IJnion C?wck-List (1910) has been followed, except where modified by the one supplement since published. There are several island races belonging to groups which have lately been monographed, and which have been accorded standings different from those in the Check-List. In such cases, while I personally accept, for the most part, the opinions of the men who have done this work, I have in 6 PACIFIC COAST AVIFAUNA No. 12 this publication been content to state their findings in the text, without changing the formal headings under which these species are placed. This appeared to be the best plan, in the interests of convenience and uniformity. Jn the treatment of records objection may be made that some unconfirmotl ones are included, while others, at first glance apparently just as trustlvorthy, are relegated to the hypothetical list. I have endeavored to act conservatively in this; but one need not be as strict in such matters in the case of a local paper as in a state list, and I have therefore accepted sight records, by competent observ- ers, of birds not too hard to identify in the field and belonging to such species as one might expect to find upon the islands. On the other hand, in the case of sin- gle, sight records, of birds that are especially hard to differentiate in life from closely allied forms, relegation to the hypothetical list has been the only course open to me. As regards another type of record: We know that Dr. J. G. Cooper was a most capable and scrupulous ornithologist; but in his time men did not keep as exact notes, nor label their specimens with as much care, as they now do. I find that several of Coopers’ island skins were wrongly identified, while there seem to be a number of mistakes and inconsistencies in his published notes. Therefore, any unusual records of his, unless verified, have been placed in the hypothetical list. In the cases of birds that do not breed upon the islands, it is often difficult to judge as to their numbers and the regularity of their visits. Therefore, in- stead of merely citing a few winter records without any explanation, I have stated, when there are instances of the occurrences of a species upon more than one island, the probable numbers in which it is found, judging from its relative a.bundance on the nearby mainland and the apparent likelihood of its occurring regularly upon the islands. In general I have endeavor(ld, besides giving man- ner of occurrence, to present any little-ltnotl-n habits that may be of interest, especially those relating to species or subspecieswhich are confined to the islands. Generally speaking, it is a bad plan in any science to advance fanciful theo- ries, impossible to prove; for a science should be built up of facts. With some: things, however, as for example, with bird migration, it is impossible to make absolute statements as to cause and effect, and in such cases it seems justifiable to advance theories, which, even though eventually shown to be incorrect, do good by promoting further discussion. With such an idea I have submitted several theories in the following chapter on “Problems presented by the island avi- fauna , ’ ’ the resulting conclusions, though not considered as absolutely proven, having been reached through careful consideration of the known facts. While not submitted as final, I trust that they may prove of a,ssistancein building up a further understanding of our insular bird life. ACKNOWLEDGMENTS During the preparation of the following paper I have often called upon fel- low members of the Cooper Ornithological Club for aid, which, though some- times incurring trouble on their part, has at all times been most cheerfully and promptly rendered. For furnishing me with important unpublished notes in re- gard to the island birds, I am very greatly indebted to the following gentlemen: W. L. Dawson, D. R. Dickey, 0. W. Howard, L. M. Huey, C. C. Lamb, J. Maill- iard, C. W. Richmond and G. Willett; and for supplying much needed informa- tion of various kinds, to C. B. Linton, H. C. Oberholser, A. van Rossem, and H. S. Swarth, the latter having been of great help to me in many ways. I am under obligation to F. S. Daggett for allowing me access to the collections in the Mu- seum of History, Science and Art, of Los Angeles; to J. E. Thayer for the loan of specimens and for notes; t,o the Bureau of Biological Survey, .through E. W. Nelson, for the loan of specimens ; to the Museum of Vertebrate Zoology of th(a University of California for access to its collections, a.nd for the loan of speci- mens.; and to W.