354 BULLETIN 2 03, UNITED STATES NATIONAL MUSEUM 



"Ground color a dull greenish gray-white, in a large series the pe- 

 culiar color of the markings seem to tinge the ground color ; the mark- 

 ings are very mixed, numerous under shell marks, in the form of 

 blotches and specks, of pale lavender and purplish gray overlaid with 

 heavier surface markings of wine-red, umber and deeper shades of 

 purplish gray and blackish. The heaviest markings are at the larger 

 end, which is sometimes well wreathed, with many spots and specks 

 over rest of egg." The measurements of 50 eggs average 17.1 by 13.0 

 millimeters ; the eggs showing the four extremes measure 19.0 by 13.6, 

 17.6 by 14.0, 15.4 by 12.7, and 16.0 by 11.9 millimeters.] 



Plumages. — [Author's Note: Dr. Dwight (1900) describes the 

 Juvenal plumage, in which the sexes are apparently alike, as "above 

 olive-brown with dull black streaking. Below, dull white, streaked 

 with clove-brown chiefly anteriorly." A postjuvenal molt, beginning 

 early in June in Florida, and involving the contour plumage and the 

 wing coverts but not the rest of the wings or the tail, produces the 

 first winter plumages. These are much like those of the adults, but are 

 generally more brownish, the female being browner than the male. 

 The yellow throat is assumed at this molt. 



The first nuptial plumage is acquired by wear, the brownish wash 

 wearing away and the back becoming grayer and the black markings 

 clearer. Young birds are now indistinguishable from adults, except 

 by the browner and more worn wings. 



Adults have one complete postnuptial molt in midsummer, after 

 which the fully adult plumage is assumed, the colors of the female 

 being similar to those of the male but duller.] 



Food — The food of the yellow-throated warbler has apparently not 

 been well investigated. Little appears in the literature, an illustra- 

 tion of the need to learn more of the diet of small, woodland birds. 

 Records of the examination of seven stomachs reveal that insects com- 

 pose most of its diet, for according to Howell (1932) "beetles, moths 

 and their larvae, flies, bugs, grasshoppers, grouse locusts, crickets, 

 scale insects, and spiders" are included in the food. Witmer Stone 

 (1937) in writing of the first observance of this warbler at Cape May 

 Point, N. J., on July 13, 1920, states that he saw it take "a green cater- 

 pillar about an inch in length." D. J. Nicholson has noted (1929) 

 that while watching one of these birds in Volusia County, Fla., he 

 saw it eat at least ten "worms" in a few minutes as it searched the trees 

 near where he sat. 



I have often watched these warblers feeding in my yard and have 

 seen them take small, active caterpillars on numerous occasions. 

 There seems little doubt that scale insects are often taken, as the 

 yellow-throated warbler, creeping about the limbs of trees as it does, 

 undoubtedly finds many of these tiny, but destructive pests. There 

 can be little question as to its benefit to agriculture. 



