Mrs. Allen writes to me from Berkeley, Calif.: “Breeding birds leave the bay region in late July or early August; migrants from farther north begin to go through in September; the latest date on which I have seen them is October 16, 1920. I usually see them in the shade trees along the streets or in the woods when they come to bathe in my bird pool. But I have two records which show them in very different situations: September 18, 1933, on a hill slope that had been recently burnt over, a group of these warblers with horned larks and Savannah sparrows; and on September 25, 1941, at Point Reyes lighthouse, hunting for food in the low, dry lupines just inside the rocky point. One could not help wondering if they had just come to a landing place after a long flight over the ocean. They were in immature plumage.”
According to the 1931 Check-List, the California yellow warbler “migrates through eastern California, Arizona, and Lower California; winters sparsely in the Cape District of Lower California and south to Guatemala, Nicaragua, and Costa Rica.”
Winter.—Dickey and van Rossem (1938) record this warbler as a “winter visitant and spring migrant in the Arid Lower Tropical Zone,” in El Salvador. “The small Pacific coast race, brewsterii, is apparently relatively the least common of the four forms found in El Salvador; at any rate, the small number of specimens taken indicates that this is the case. Yellow warblers were common in January at Puerto del Triunfo and in February at Rio San Miguel, but unfortunately only one specimen was taken at each place. Whether all of these winter birds were brewsteri and morcomi is problematical.”
DENDROICA PETECHIA SONORANA Brewster
SONORA YELLOW WARBLER
HABITS
This is the palest of all the yellow warblers, one of the many pale races of the southwestern desert regions. Its breeding range extends from southeastern California, southern Utah, Arizona, and New Mexico to central western Texas, Sonora, and Chihuahua; and it winters from Mexico southward to Guatemala, Nicaragua, and Costa Rica.
It is best described by Ridgway (1902) as “similar to D. æ. æstiva, but much paler; adult male lighter and much more yellowish olive-green above, the back frequently (usually?) streaked with chestnut, pileum usually wholly clear yellow, lower rump and upper tail-coverts yellow, faintly streaked with olive-greenish; wing edgings all yellow; under parts lighter yellow than in D. æ. æstiva, and with chest and sides much more narrowly (often faintly) streaked with chestnut; adult female conspicuously paler than in D. æ. aestiva, the upper parts often largely pale grayish, the under parts usually very pale buffy yellow.”