g and summer, and may
be seen in flocks flying and feeding in company with the red-winged
blackbirds. They are often found among the cattle and sheep in the
pastures and barn-yards, and they derive all of their common names from
this habit. Although nearly related to the orioles, which make such
wonderful nests, the cow-birds make none at all, but lay their eggs in
the nests of other birds, such as the blue-bird, chipping-bird,
song-sparrow, yellow-bird, and some thrushes and fly-catchers. Like the
cuckoo, this bird usually chooses the nest of a bird much smaller than
itself, but as its egg is not small, the deception is at once
discovered, and the birds whose nest has been selected for this purpose
are very much disturbed. It is necessary for the female cow-bird to find
a nest in which the owners have just begun laying, for if the owners
have no eggs of their own they will desert the nest, and if their own
eggs are somewhat advanced before the cow-bird's egg is laid, their own
young will hatch first, and the parents will then leave the nest to hunt
for food, thus allowing the cow-bird's egg to become cold and die.

When the female cow-bird is ready to lay her egg, she often has great
trouble in discovering a nest at just the right stage. She leaves the
flock and perches upon some tree or bush, where she can have a good view
of all that is going on. When she discovers a nest by watching the
actions of its owners, she waits for an opportunity when both the owners
are away, when she approaches it very stealthily, but quickly, keeping a
very sharp watch, to be sure that she is not observed. If she finds that
the nest is fit for her purpose,--that is, if the birds have laid only a
part of their regular number of eggs,--she drops one of her own eggs
into it, and then disappears as swiftly and quietly as she came. If she
is unable to find a suitable nest in her own vicinity, she goes in
search of one, examining every thicket and bush--sometimes for a long
distance--until she finds one. A gentleman once followed a cow-bird
along the shore of a stream for two miles before she succeeded in
finding a nest which satisfied her. Occasionally, two or more cow-birds'
eggs are found in the same nest. It is not known whether both of these
are laid by the same bird, but it is more probable that in such a case
as this two cow-birds have visited the same nest.

The egg of the cow-bird has one interesting and important peculiarity.
It is n