502 THE BIRDS OF MAINE 



every minute or so during the day in early summer and dili- 

 gently assists the female in nest building, both by actual 

 construction work and well timed song of encouragement. 



Alders, bushy thickets, shrubbery in gardens, orchard trees 

 and thickets along banks of streams and rivers are selected as 

 nesting sites. The nest is a very compactly built and well 

 cupped structure, composed of fine soft grasses and rootlets, 

 soft hempen fibers, cottony down from the willow catkins, 

 pieces of thread, twine, cloth, shreds of paper, and similar soft 

 material, lined with willow down and a few feathers. A typi- 

 cal nest from which the foregoing description is made measures 

 two and a quarter inches in height outside, depth of inside 

 cavity one inch, diameter at bottom outside two and a half 

 inches, diameter of cavity across top one and a half inches. 

 This particular nest was situated in a small bunch of alders 

 thirty-three inches from the ground in a bushy meadow along 

 the Stillwater River at Orono. 



The eggs are of a greenish white ground color, very heavily 

 wreathed with cinnamon brown, black and lilac about the 

 larger end, and measure 0.66x0.52, 0.67x0.51, 0.67x0.51, 

 0.68x0.51. Other eggs seen sometimes have a bluish white 

 ground color, and the markings are sometimes more inclined 

 to umber brown. Generally the eggs are wreathed about the 

 larger end rather heavily, but sometimes the eggs are only 

 slightly or not at all wreathed, and while nearly always a few 

 small spots are loosely scattered over the surface, sometimes 

 the whole surface is quite evenly dotted. 



Nest building, which both parents assist in, requires a 

 period varying from a week to ten days and fresh eggs may be 

 found from May twenty-ninth to even as late as early July. 

 It seems quite likely that these late sets may result from the 

 birds having been robbed or otherwise disturbed in their first 

 efforts. Sometimes a Cowbird deposits its egg in a Yellow 

 Warbler's nest, in which case they often build a new nest on 

 top of the old one, thus effectually stifling the intruding egg, 



