George Willett: Naturalist, Ornithologist and First Curator of L.A. County Museum of Natural History, Edited and Compiled by Robert Roy van de Hoek

A REVISED LIST OF THE BIRDS OF SOUTHWESTERN CALIFORNIA
by
GEORGE WILLETT
CONTRIBUTION FROM THE LOS ANGELES MUSEUM
Cooper Ornithological Club
Pacific Coast Avifauna Number 21
Los Angeles, California
Published by the Club
December 1, 1933

Compiled by Robert “Roy” van de Hoek, March 29, 2000.

ACKNOWLEDGEMENTS
I am under great obligations to Louis B. Bishop, Joseph Grinnell, Loye H. Miller, A.J. van Rossem and Harry S. Swarth,...
George Willett
Los Angeles, California,
October 1, 1933.

INTRODUCTION
Since the publication of Avifauna Number 7, 1912, more than twenty years have passed. ..... In addition to this, when we consider the changes in bird population brought about by bringing under cultivation a large percentage of hitherto wild land, as well as by introduction of foreign species, it is clear that our bird list of more than twenty years ago is subject to much emendation.

In studying the birds in the channel between San Pedro and Catalina Island, the writer has found that occurrence of open-water groups, such as shearwaters, petrels and jaegers, in any particular locality, varies greatly from year to year....
Gavia immer (Brunnich)
Common Loon
Synonyms: Lesser Loon
Common winter visitant along coast; also occurs on inland lakes and ponds. Arrives in October and leaves mostly in late April and early May, but immature birds occasional in summer. Noted by W.L. Dawson near Santa Barbara June 25, 1914, and May 29 and June 15, 1915 (Condor, 18, 1916:23), and by G. Willett at Manhatten Beach, Los Angeles County, July 6, 1911, and at Bolsa Chica, Orange County, July 24, same year (Pac. Coast Avif., No. 7, 1912:10). Reported by J.G. Cooper as abundant in winter in San Diego Bay, some remaining as late as May (Baird, Brewer and Ridgway, W.B.N.A.,2,1884:447).

L.B. Bishop has shown that the Common Loon is somewhat larger in the more norther part of its range than it is further south, and has called the more southern bird Gavia immer elasson (Auk, 38,1921: 364-370). Although this latter name is used in the 1931 A.O.U. Checklist, the writer feels that its characters are hardly pronounced enought to warrant the division of immer.

Gavia arctica pacifica (Lawrence)
Pacific Loon
Common winter vistant on ocean; particularly abundant around Santa Barbara Islands. Arrives in September and remains until late May.