BIRDS OF FIELD AND GARDEN. 321 
Throughout the season the sexes intermingle promiscu- 
ously, from the time the females arrive in the spring. As 
usual with other species, the males come first, and may be 
seen singly, in small flocks, or with other species of Black- 
birds. They perch in the tops of tall trees, and their only 
song is a long, thin whistle, high keyed and little varied. 
The common note is a chuck. 
The females soon arrive from the south, and then flocks 
may be seen in which they usually predominate. The eggs 
are deposited from April to June, in the nests of other and 
usually smaller birds. An egg is dropped slyly when the 
owner of the nest is absent, and generally after she has laid 
some of her own. Sometimes the little foster mother refuses 
to adopt the offspring of another, and abandons the nest, 
or builds another nest above the first one; but usually she 
good-naturedly settles down upon her nest to incubate. 
The Cowbird’s egg is larger than those of the foster mother, 
and is commonly deposited in the center of the nest. Per- 
haps it gets more heat than the other eggs, for it hatches first. 
The young Cowbird grows faster than the other chicks, and 
gets about all the food. Itis soon able to dislodge its smaller 
and weaker foster brothers and sisters, who perish ; then the 
young Cowbird monopolizes the entire time and care of its 
foster parents. It is no uncommon thing to see a small War- 
bler or a Chipping Sparrow feeding a young Cowbird twice 
its own size; but as soon as the stranger is well able to 
shift for itself, it joins a flock of its own species. 
Grasshoppers seem to be its favorite animal food, but leaf 
hoppers, also very destructive to grass, are freely taken. 
Undoubtedly the Cowbird is of great benefit to- pastures, 
where it follows the cattle about, picking up insects that 
start up around them. Weevils and curculios are commonly 
eaten ; also caterpillars, but to a less extent than other Black- 
birds eat them. Cowbirds take wasps, ants, and flies in small 
quantity,anda number of spiders. Vegetable food, however, 
forms the main part of the Cowbird’s subsistence in spring 
and fall, and, according to Professor Beal, it constitutes 
nearly seventy per cent. of all the food for the year. A 
large part of this, however, is weed seed, of which the seed 
