168 BIRDS OF PENNSYLVANIA. 



than herself, she also, at times, drops eggs in nests of larger species^ 

 Dr. Coues mentions among the Cowbird's larger foster-parents, the 

 Wood Thrush, Yellow-breasted Chat, Kingbird and Towhee Bunting; 

 on one occasion I saw two eggs in the nest of a Cardinal Grosbeak, 

 and have twice seen eggs in nests of Wood Thrushes. Both nests of 

 the species last named were, however, abandoned. From the fact 

 that one Cowbird's egg is usually seen in a nest, I judge that this bird 

 only deposits a single egg in a nest. I, of course, am well aware that 

 sometimes two, three or more Cowbird eggs may be discovered in a 

 single nest, yet this is no evidence that these eggs were deposited by 

 one bird. The number of eggs which this bird lays is unknown ; they 

 are white, speckled or blotched with brown * vary greatly in size, but 

 average, probably, about .88 in length and .65 in width. In addition 

 to the species previously named, I have found Cowbirds' eggs or 

 young in charge of the following named birds : Red and White Eyed 

 Vireos, Ovenbird, Maryland Yellow-throat, Scarlet Tanager, Song 

 and Chipping Sparrows, Indigobird, Worm-eating Warbler, Acadian 

 Flycatcher and Baltimore Oriole. This species frequents ploughed 

 fields, woods and pasture grounds, mingles freely among cattle and 

 may often be observed perched on their backs. The food of these 

 birds consists of seeds, grains, berries and insects. Although Cow- 

 birds subsist to a small extent on wheat and rye, they never, I 

 think, like the English Sparrow, attack these cereals when growing. 

 The seeds of clover, timothy, fox-tailed grass, bitter-weed, etc., are 

 included in their bill of fare ; blackberries, huckleberries, cedar- 

 berries, wild cherries and the summer grape ( Vitis cestivalis, Mz.,) 

 are eaten. They subsist to a very great extent, however, on insects; 

 large numbers of grasshoppers, beetles, grubs and " worms'' are 

 eagerly devoured. 



GENUS AGELAIUS. VIEILLOT. 

 498. Agelaius phoeniceus (LINN.). 



Red-winged Blackbird; Swamp Blackbird. 



DESCRIPTION. (Plate 37.) 



Bill, legs and feet (dried specimens) black ; iris brown ; male larger than female. 



Adult male. General color uniform lustrous velvet-black, shoulders and lesser- 

 wing coverts of a bright crimson or vermillion-red ; middle coverts brownish-yel- 

 low ; in autumn and winter the back and scapular feathers, particularly, are con- 

 spicuously bordered with rusty. Florida specimens are smaller and more glossy 

 than Pennsylvania specimens. 



Adult female. Brown above, the feathers edged or streaked with rufous-brown 

 and yellowish ; beneath whitish, streaked with brown ; stripe on crown and over the- 

 eye strongly tinged with brownish-yellow; throat, chin, edgeofwing, tinged with pink 



