MOURNING WARBLER 527 



Eggs. — The mourning warbler lays from 3 to 5 eggs to a set, more 

 often 4. They are ovate with a tendency toward short ovate and have 

 a slight gloss. The ground color is white, or creamy white, and is 

 speckled, spotted, or blotched with "bay," "chestnut," and "auburn," 

 with underlying spots of "light vinaceous drab," "brownish drab," or 

 "drab-gray." In addition to these markings, many eggs have a few 

 scattered spots, or very small scrawls of black. Although there is a 

 tendency toward concentration of markings at the large end, manj^ 

 eggs are finely and delicately speckled over the entire surface. The 

 measurements of 50 eggs average 18.2 by 13.8 millimeters; the eggs 

 showing the four extremes measure 20.0 by 14.2, 19.9 by 14.7, 16.5 by 

 13.7, and 17.7 by 13.2 millimeters (Harris). 



Plimiages. — ^Dr. D wight (1900) says that the juvenal plumage of 

 the mourning warbler is "very similar to G. trichas but darker. 

 Above deep olive-brown. Wings darker, edged with olive-green, the 

 coverts faintly edged with pale cinnamon. Tail deep olive-green. 

 Below, very deep grayish tawny-olive, abdomen and crissum pale 

 brownish Naples-yellow. Inconspicuous orbital ring pale buff." 



The postjuvenal molt, which involves the contour plumage and 

 the wing coverts, but not the rest of the wings or the tail, occurs in 

 August and is completed before the birds reach their winter home. 

 Dr. Dwight describes the male as "above similar to G. trichas and to 

 G. agilis but greener than either, with a plumbeous tinge about the 

 head, and the yellow below brighter. There is usually a little con- 

 cealed black on the throat ; the chin is yellowish white. The conspicu- 

 ous orbital ring and a supraloral line are pale canary-yellow, the 

 lores dusky." 



The first nuptial plumage is "acquired by a partial prenuptial moult 

 which involves chiefly the head and throat. The plumbeous cap, the 

 black throat veiled with cinereous, the dusky lores and the white 

 orbital rings are assumed, the rest of the plumage showing a good 

 deal of wear." This and subsequent prenuptial molts occur in late 

 February and March, before the birds come north. 



Adults have a complete postnuptial molt in August and a partial 

 prenuptial molt as in the young birds. Of the female, he says : "The 

 plumages and moults correspond to those of the male. In first winter 

 plumage the throat is browner and in but slight contrast to the breast, 

 scarcely distinguishable from the male first winter dress of G. agilis. 

 The first nuptial plumage is acquired chiefly by wear. The adult 

 winter plumage resembles the somewhat grayer first winter male." 

 No black is assumed on the throat. 



Food. — No one seems to have made a study of the food of this war- 

 bler. Dr. B. H. Warren (1890) mentions beetles and spiders in the 



