WILSON'S PILEOLATED WARBLER 629 



covered during the nesting season is on account of the favorite habitats being 

 rarely visited by ornithologists. Full sets of eggs may be sought between June 

 first and June nineteenth. There seems to be no doubt at all that a person, 

 acquainted with the habits of the present species and the Yellow Palm Warbler 

 as well, can go into territory in northern and central Maine and find both 

 species in many localities where other observers have failed to see them, pro- 

 vided that suitable tracts of spruce and hackmatack bog exist in the region. 



Horace W. Wright (1911) speaks of the bird as "a rare summer 

 resident, but becoming less rare" in Jefferson, N. H. He found the 

 birds settled in Jefferson in the summer of 1905, and during the fol- 

 lowing 5 years, a little colony of six males was established. He reports 

 also a nest and eggs found in 1909 by F. B. Spaulding in the neighbor- 

 ing town of Lancaster. 



Eggs. — ^Wilson's warbler lays from 4 to 6 eggs to a set, most com- 

 monly five. These are ovate, with some tending toward short ovate, 

 and they have only a slight lustre. They are white, or creamy white, 

 finely sj^eckled or spotted with "chestnut," "auburn," or "russet," with 

 underlying markings of "light brownish drab" or "pale brownish 

 drab." Sometimes the markings are scattered well over the egg, but 

 there is a tendency to concentrate at the large end, often forming a 

 distinct wreath of fine specklings. On the more boldly marked eggs 

 the drab tones are quite prominent, whereas on the finely marked eggs 

 they are often absent. The measurements of 44 eggs average 15.9 by 

 12.4 millimeters ; the eggs showing the four extremes measure 17.3 by 

 12.7, 16.8 by 13.2, and 14.0 by 11.4 millimeters (Harris). 



Young. — Two nests under the observation of W. J. Brown (MS.) at 

 Matane County, Quebec, contained five fresh eggs on June 18, 1939. 

 "The young appeared in both nests in the early morning of June 29. 

 On July 10 both nests were empty. On the basis of these records, the 

 incubation period lasts 10 to 11 days, and the young remain in the 

 nest for the same length of time." 



Plumages. — Dr. Dwight (1900) describes the juvenal plumage, in 

 which the sexes are alike, as follows: "Above, sepia or hair brown, 

 mottled with sepia. Wings and tail dull olive-brown, edged with 

 olive-green; wing coverts paler and indistinctly edged with buff. 

 Below, primrose-yellow washed with pale wood-brown on the throat 

 and sides." 



The first winter plumage is acquired in July and involves a molt 

 of all the body plumage and the wing coverts, but not the rest of the 

 wings or the tail. The black cap is acquired, veiled with brownish 

 feather tips ; the upper parts become bright olive-green ; the forehead, 

 sides of the head, and the under parts become lemon-yellow. 



The first nuptial plumage is acquired by a partial prenuptial molt, 

 chiefly about the head and tliroat, young and old birds becoming 

 indistinguishable. 



081873—53 41 



