Cowbird (Molothrus ater)
Cowbirds are the only native American birds to always lay their eggs
in nests of other species, and have the young raised by foster
parents. Warblers, finches, and sparrows, all smaller than cowbirds,
are the chief victims of this practice, the fast growing foster chick
monopolizing food and space to the detriment of the legitimate
offspring.
This is the smallest blackbird, flocking in small groups, or mixing with
grackles and red-wings. They are usually quiet, their only song a
faint whistle. They range north into Canada and winter in the
southeastern States. Grasshoppers, beetles, and a number of
insects are eaten, and like other blackbirds, they do some damage to
grain.