126 



BIRDS OF AMERICA 



YELLOW WARBLER 

 Dendroica aestiva asstiva ( tiinclin) 



A. O. U. Number 05.' See Color I 'Lite 95 



Other Names. — Summer Warbler ; Yellow Tit- 

 mouse : Summer Yellowbird ; Yellowbird ; Yellow Poll ; 

 Blue-eyed Yellow Warbler : Golden Warbler : Wild 

 Canary (incorrect). 



General Description. — Length. 4J4 inches. Fore 

 and under parts, yellow ; upper parts, yellowish olive- 

 green ; under parts, streaked with chestnut. Bill, 

 shorter than head, slender, tapering gradually to the 

 tip ; wings, moderately long and pointed ; tail, slightly 

 rounded. 



Color. — Adult Male: Gcncnil color above, ycllozv- 

 ish oUvc-grccn, the crown more yellowish, usually clear 

 yellow on forehead and on the forward portion of 

 crown, often tinged with orange-tawny; upper tail- 

 coverts edged with yellow ; back, sometimes streaked 

 with chestnut; wings and tail, dusky, the middle wing- 

 coverts broadly tipped with yellow, the greater wing- 

 coverts and inner wing-feathers broadly edged with 

 the same; primaries, more narrowly edged with yellow- 

 ish olive-green; inner webs of tail-feathers yellow, 

 tipped with dusky; sides of head and under parts, clear 

 rich yellow, the chest, sides, and flanks, streaked ivith 

 chestnut: bill, blackish; iris, brown; legs and feet, light 

 brownish. .A.DULT Female : Above, plain yellowish 



olive-green (usually darker than in adult male), the 

 crown concolor with the back, or at least not distinctly 

 more yellowish ; wings and tail, as in adult male, but 

 tips of middle wing-coverts and broad edgings of 

 greater coverts and secondaries less purely yellow, 

 usually yellowish olive-green ; under parts, paler and 

 duller yellow than in adult male, usually without 

 streaks, but sometimes with a few, usually indistinct, 

 chestnut streaks on chest and sides. 



Nest and Eggs. — Nest: Generally located in hedges 

 and small saplings, within 10 feet of the ground, and 

 strongly fastened in forks; constructed very neatly of 

 grayish colored plant fibers and slender pliable strips 

 of bark and lined with down and feathers; in some 

 cases built entirely of cat-tail down forming an exqui- 

 sitely soft receptacle for eggs and young. Eggs: 2 to 

 6, usually 4, with a greenish white ground spotted and 

 splashed around large end with shades of brown, lilac- 

 gray, and some black. 



Distribution. — North and South America ; breeds in 

 North America east of Alaska and Pacific slope from 

 tree limit south to Nevada, northern New Mexico, 

 southern Missouri, and northern South Carolina ; 

 winters from Yucatan to Guiana, Brazil, and Peru. 



Photo by H. T MM.M. t , 



MOTHER YELLOW WARBLER 

 Feeding her one-day-old babes 



The Yellow Warbler seems to be one of the 

 few birds, and represents perhaps the only 

 species, which resent and often defeat the Cow- 

 bird's parasitic practice of laying its eggs in the 

 nests of other birds and of unloading upon them 

 its parental responsibilities. This the bird does 

 by building a flooring over its eggs among which 

 a Cowbird has deposited one of her own. That 

 the bird does this deliberately, and with the defi- 

 nite purpose of avoiding the hatching and rear- 

 ing of the ugly and voracious foundling, is shown 

 by the fact that the intended victim of the Cow- 

 bird frequently repeats the floor-building opera- 

 tion twice or even three times, to forestall as 

 many of the parasite's attempts to make it a 

 foster parent. Why the Yellow Warbler should 

 be apparently capable of this discernment, and 

 should resent and defeat the intended imposition, 

 while other Warblers, not to mention various 

 Vireos and Sparrows, evidently not only make 

 no effort to get rid of the egg, but feed the young 

 Cowbird as solicitously as they feed their own 

 voung, is one of Nature's riddles of which there 

 appears to be no solution. 



For many other reasons besides this eminently 

 practical one, the Yellow Warbler makes a 

 strong appeal to our affections and respect. In 



