WOOD WARBLERS 
411 
zona between 9000 and 10,000 feet, the male following the female 
ibout while she collected material for the nest, uttering at times ‘ a 
liquid quirt, quirt, quirt, in a descending scale.’ 
Fig. 520. 
unstreaked. 
Subgenus Dendroica. 
652. Dendroica sestiva ( Gmd .). Yellow Warbler. 
Adult male. — Under parts yellow ; breast and belly streaked with rufous ; 
forehead bright yellow, front of crown often tinged with 
orange; hind neck and rest of upper parts yellowish 
green, brightest on rump; wing edgings yellow; inner 
webs of tail feathers, except middle pair, light yellow. 
Adult female and male in Jirst autumn : upper parts plain 
yellowish green, usually darker than in male, lighter on 
forehead and rump ; under parts paler and duller, usually 
Young female in first autumn: like adult female, but duller 
olive green above, olive whitish slightly tinged with yellow below ; under 
tail coverts pale yellow. Male: length (skins) 3.94-4.92, wing 2.36-2.80, 
tail 1.65-2.09, bill .S9-.43. Female: length (skins) 4.02-4.57, wing 2.24- 
2.68, tail 1.54-1.77, bill .39-.43. 
Remarks. — The yellow on the inner webs of the tail feathers, together 
with the general yellow coloration, are enough to distinguish the (estiva 
group in all ages and sexes. 
Distribution. — North America, except Alaska and southwestern United 
States ; migrates to Central America and northern South America. Breeds 
nearly throughout its North American range. 
Nest. — Compact and cup-shaped, made largely of gray plant fibers, 
lined with down and feathers ; placed in bushes or trees. Eggs: 2 to 6, 
greenish, spotted usually around larger end with brown, black, and lilac 
gray. 
Food. — Insects. 
The yellow warblers are birds of the chaparral, of willows, and 
thickets along streams in uninhabited regions, and of parks and 
gardens where the gods provide. When seen in the chaparral thick¬ 
ets the glimpse of yellow tail patches is enough to identify them as 
they disappear, but in towns where they are tame the bricky streak¬ 
ing of the breast can be seen as they stand on a flowering bush and 
lift their heads to sing. They have so much singing to do and so 
many insects to catch that it keeps them busy. Their song is loud 
and cheery and they have the fine chip of their family. In their 
manner of life they belong to the quiet part of the warbler tribe, 
hunting usually in a leisurely way as if they knew that their song 
was needed to add the real summer feeling to the blooming shrubs. 
652a. D. a. sonorana Brewst. Sonora Yellow Warbler. 
Like (estiva, but much paler ; adult male lighter, more yellowish olive 
green above, back often streaked with brown, crown usually clear yellow ; 
under parts lighter yellow than in cestiva; chest and sides more narrowly 
streaked ; adult female conspicuously paler than in (estiva, upper parts often 
largely pale grayish ; under parts usually pale huffy yellow. Male: length 
(skins) 4.21-4.76, wing 2.32-2.60, tail 1.77-2.20, bill .39-.43. Female: 
length (skins) 4.33-4.57, wing 2.24-2.40, tail 1.65-1.77, bill .39. 
