Nature Bulletin No, 229   May 8, 1982
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

****:THE MOCKINGBIRDS

The Mockingbird, the Catbird and the Brown Thrasher are called 
"mockers' or mimics because, in addition to the superb quality and 
variety of their natural songs, they imitate those of other birds. Most 
versatile and famous is the mockingbird which may not only reproduce 
phrases borrowed from as many as twenty birds in its neighborhood 
but also the barking of a dog, the cackling of a hen, the squeal of a pig, 
or even the squeaking of a wagon wheel. The length of the phrase may 
vary from a single note, such as the caw of a crow, to the song of a 
robin. The catbird is not as accomplished a mimic but excels the 
brown thrasher. The mockingbird repeats each phrase three or more 
times: the brown thrasher usually repeats once; and the catbird does 
not repeat at all.

The mockingbird is about the size of a robin except that it is more 
slender and has a longer tail. Both sexes have brownish-gray backs, 
are whitish or grayish below and, on the wings and tail, have large 
white markings which are especially conspicuous in flight. It is 
abundant in the southern states, and is the official bird of Florida, 
Tennessee, Mississippi, Arkansas and Texas. A few are seen in the 
Chicago and other northern regions every year. It prefers open areas 
with a few trees and dense shrubbery, near towns and farms, where the 
male pugnaciously defends a territory against cats, snakes, hawks and 
other birds. The bulky nest of sticks, weeds and trash, vined with 
root1ets, horsehair and cotton, is built in a shrub or small tree and in it 
are laid from 3 to 5 eggs -- greenish, buffy or blue; blotched with 
brown or purplish spots. Frequently, three broods are reared in a 
season .

In addition to music borrowed from other birds, often interrupted by 
harsh grating calls, the male is famous for his rapturous mating song 
which is a gurgling series of sweet liquid notes, sung not only in 
daytime but throughout moonlight nights. In spring and early summer 
they feed largely upon insects, including many injurious kinds. Later, 
their food is largely berries, seeds and wild fruits.

The brown thrasher, "Mockingbird of the North," is common 
throughout the United States and southern Canada east of the Rockies. 
Its loud clear mating song is a brilliant medley of short emphatic 
phrases, usually sung from the top of some tall tree. A little longer and 
slimmer than a robin, with a long tail like the other mockers, both 
sexes are colored alike; rich reddish-brown above, with a creamy 
breast heavily and darkly streaked. They spend much of their time on 
or near the ground. The bulky well-lined nest is built in a low thorny 
tree, a vine-entangled bush, or even on the ground; and contains 4 or 5 
whitish or greenish-white eggs with reddish-brown dots. The parents 
make clicking and hissing noises if the nest is approached. Two broods 
are usually raised each year. In spring and summer they feed on 
insects, spiders and worms, most of which they gather from beneath 
fallen leaves; later on wild fruits, acorns and waste grain.

The catbird, so-called because of its catlike mewing cry when 
disturbed, is common throughout much of the United States and 
southern Canada. Smaller than the thrasher, both sexes are blue-gray 
with black caps. It, too, prefers thickets and dense shrubbery near 
towns and country homes, but the catbird sings from concealment and 
his beautiful mating song -- as sweet but not so loud as the thrasher's -
- is frequently heard on moonlight nights. He cleverly imitates other 
birds and harsh noises. In autumn he has a "whisper" song which is 
barely audible. She lays 4 to 6 glossy blue-green unmarked eggs in a 
well-hidden bulky nest, usually twice each year.

The catbird is a copycat.