282 BIRDS OF ONTARIO. 



in these flocks from three to four of a different species have been 

 prevented from coming to maturity. 



The number of species imposed upon by the Cowbird is large, 

 including Warblers, Vireos, Sparrows, Thrushes, Bluebirds, etc., but 

 the one most frequently selected in this locality is the Summer 

 Yellowbird. On the prairies, where the Cowbirds are numerous, and 

 the number of foster-parents limited, it is said that in the month of 

 June nearly every available nest contains an egg of the Cowbird. 



In Southern Ontario they disappear during July and August, but 

 usually return in vast flocks in September, when they frequent the 

 stubble fields and patches of wild rice by the edge of the marshes. 



Genus XANTHOCEPHALUS Bonaparte. 

 XANTHOCEPHALUS XANTHOCEPHALUS (Bonap.). 



203. Yellow-headed Blackbird. (497) 



Male : — Black ; whole head (except lores), neck and upper breast, yellow, 

 and sometimes yellowish feathers on the belly and legs ; a large white patch 

 on the wing, formed by the primary and a few of the outer secondary coverts. 

 Feviah and yonng : — Brownish-black, with little or no white on the wing, the 

 yellow restricted or obscured. Female much smaller than the male, about 9^. 

 Length, 10-11 ; wing, 5^ ; tail, 4^. 



Hab, — Western North America, from Wisconsin, Illinois and Texas to the 

 Pacifio coast. Accidental in the Atlantic States (Massachusetts, South Carolina, 

 Florida). 



Nest, composed of aquatic grasses fastened to the reeds. . 



Eggs, three to six, grayish-green spotted with reddish-brown. 



A wanderer from the west, this handsome Blackbird has appeared 

 from time to time at different points in the Eastern States. The 

 only record I have of its occurrence in Ontario is that given by Mr. 

 E. E. Thompson, in the Auk for October, 1885, as follows: "This 

 species has been taken a number of times in company with the 

 Red-winged Blackbirds by Mr. Wm. Loane, who describes it as the 

 Californian Blackbird. ~ The specimen I examined was taken near 

 Toronto by that gentleman, and it is now in the possession of Mr. 

 Jacobs, of Centre Street." 



Though the Yellow-headed Blackbird is only a casual visitor, I 

 think it is quite probable we may yet see it as a summer resident 

 in the grassy meadows of Ontario. At present it comes east as far as 

 Iowa, Minnesota, Illinois and Wisconsin, while in a northerly direc- 



