210 
BIRDS OF PENNSYLVANIA. 
herself, she also, at times, drops eg-gs in nests of larger species. Dr. 
Cones mentions among the Cowbird’s larger foster-parents, the Wood 
Thrush, Yellow-breasted Chat, Kingbird and Towhee ; on one occa- 
sion I saw two eggs in the nest of a Cardinal, 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 Cow- 
bird’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 num- 
ber 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 pre- 
viously named, I have found Cowbirds’ eggs or young in the charge of 
the following-named birds: Bed and White-Eyed Yireos, 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, ber- 
ries and insects. Although Cowbirds 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, huckle- 
berries, cedarberries, 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. 
Agelaius phoeniceus (Linn.). 
Red -winged Blackbird ; Swamp Blackbird. 
Description {Plate 27). 
Bill, legs and feet (dried specimens) black ; iris brown ; male larger than female. 
AdiUt male . — Uniform lustrous black ; shoulders and lesser wing-coverts scarlet, 
bordered- with brownish-yellow. 
Adult female . — Above dusky-brown, streaked with lighter and darker shades; 
below whitish streaked with brown ; throat, chin, edge of wing, tinged with pink or 
yellowish, but mostly pink, in the spring and summer at least. The female differs 
greatly in appearance ; the prevailing color above is brownish-black, all the leathers 
margined with reddish-brown ; some of those on the back with'" brownish-yellow, 
which, on the median and greater wing-coverts, form two bands ; the under parts 
are dull-whitish, each feather broadly streaked centrally with dark-brown ; the chin 
and throat yellowish, and but little streaked ; there is a distinct whitish superciliary 
streak along side the head, tinged anteriorly with brownish-yellow, and another less 
distinct in the median line of the crown. The young male, at first very similar to 
