PACIFIC AUDUBON'S WARBLER 269 



are abundant in the aspens, being "by far the most numerous species 

 of bird." 



Winter. — Audubon's warbler is a hardy bird. At least some indi- 

 viduals remain in winter almost up to the northern limit of its breed- 

 ing range; and while it retires entirely from its summer haunts in 

 the mountains, most of its breeding range elsewhere is not wholly 

 deserted. It probably remains as far north as it can make a living ; 

 its adaptability in finding a food supply helps in this and makes it 

 one of the most successful of western birds as well as one of the most 

 abundant in all parts of its range. A few remain, perhaps regularly, 

 in coastal British Columbia, for Theed Pearse has given me five 

 December dates and four February dates, spread out over a period 

 of 10 years, on which he has recorded one or more Audubon's warblers 

 on Vancouver Island; on one of these dates, February 10, 1943, the 

 temperature dropped to —6° F. 



Rathbun tells me it is "of frequent, if not regular, occurrence during 

 the winter" in Washington, And in Oregon Gabrielson and Jewett 

 (1940) record it as a "permanent resident that has been noted in every 

 county during summer and throughout western Oregon in winter. 

 * * * Its little song is heard on every side during May and June, and 

 its peculiarly distinct call or alarm note is a familiar sound throughout 

 the balance of the year. This is true not only of the wooded slopes 

 and bottoms but equally so of the weedy fence rows of the Willamette 

 Valley, where during the short days of fall and winter these warblers 

 may be found associating with the Golden-crowned Sparrows and 

 Willow Goldfinches or sitting on the telephone wires with the Western 

 Bluebirds." Swarth (1926) writes: 



In much of the West, especially in the Southwest, the Audubon's warbler is one 

 of the dominant species during the winter months. In southern California it vies 

 with the Intermediate Sparrow and House Finch in point of numbers. Wherever 

 there are birds at all, this bird is sure to be there. From the seacoast to the 

 mountains, in city parks and gardens, in orchards and in chaparral, the Audu- 

 bon's warbler is equally at home. On any country walk scores are sure to be seen, 

 starting up from the ground or out of the trees with wavering and erratic flight, 

 showing in departure a flash of white-marked tail-feathers and a gleaming 

 yellow rump spot, and uttering the incessant chip that, better than any marking, 

 serves to identify the fleeting bird. 



In colder sections there are some fatalities ; in the Fresno district, 

 according to Tyler (1913), "a period of two or three unusually cold 

 nights frequently results disastrously for these little warblers, and my 

 observations show that there is a greater mortality among this species 

 than in all other birds combined. After a hard freeze it is not an 

 uncommon occurrence to see certain individuals that appear so be- 

 numbed as to be almost unable to fly, and not a few dead birds have 

 been been found under trees along the streets." 



