Forest Preserve District of Cook County, Illinois
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Blackbirds
Nature Bulletin No. 163-A   October 3, 1964
Forest Preserve District of Cook County
Seymour Simon, President
Roberts Mann, Conservation Editor

BLACKBIRDS
A blackbird is a black bird that walks like a man. It doesn't run a few steps, like a robin, nor hop like a sparrow. It walks. Two kinds of them are abundant in this Chicago region: the Redwing Blackbird and the Bronzed Grackle. Another kind, the Cowbird, is fairly common. Most abundant, especially in cities and residential areas, is that so-called "blackbird", the Starling.

The Redwing is a marsh dweller. The males are among the earliest birds to arrive here in spring, much earlier than the females, and then we hear their joyful calls described variously as "gurgle-leee", "conk-a- reee", or "the sound of an iron gate swinging on a rusty hinge." On each shoulder they have an epaulet -- a scarlet patch fringed with yellow. Their mates, unlike the females of other blackbirds, are heavily striped. Their nests are loosely woven baskets suspended amongst rank growths of cattails or sedges.

Another marsh dweller, closely related, is the Yellow-headed Blackbird. The male has a conspicuous white wing patch and in spring his head, neck and chest are bright yellow. Formerly, great colonies of these spectacular birds nested in the vast marshes around Lake Calumet, the Skokie Marsh, and other wetlands in Cook County, but they dwindled until, this year, there was only one pair: at McGinnis Slough in the Palos preserves.

Largest of all blackbirds -- largest of all songbirds except crows and ravens -- are the grackles or 'crow blackbirds" that "strut like a lord. " The Bronzed Grackle and the Purple Grackle are closely related but the latter is rarely found west of the Appalachians and the male's back is purplish, whereas that of a Bronzed Grackle is bronzy. Both have iridescent plumage most conspicuous on the head and neck. Both have yellow eyes and a long wedge-shaped tail. The tail has a crease in the center and sometimes, especially in spring, has a keel-shaped appearance. The females are smaller than the males and their plumage has less of that metallic sheen .

Bronzed grackles nest in colonies and all sorts of places. Tall dense evergreens are favorite locations but here in Cook County they also nest in small trees such as hawthorns, and one colony nests beneath the long bridge across the Des Plaines River on US 45. They have a reputation of being cannibals who destroy the eggs and helpless young of other birds, but that has been unjustly exaggerated.

The Cowbird is a unique blackbird. It is smaller than the other kinds and its bill is sparrowlike -- relatively short and conical. The male is the only blackbird with a brown head and neck; the female is brownish gray. She builds no nest. Surreptitiously she lays her eggs in the nests of smaller birds -- usually one egg in each nest -- and then forsakes them.

Originally, this species followed the vast herds of bison that roamed the Great Plains, feeding upon ticks and insects which infested them and insects disturbed by their grazing, as well as the seeds of grasses and other prairie plants. The cowbird roamed as the buffalo roamed. Some say that is why it became a parasite like the European cuckoo.

Two other kinds of blackbirds may be seen here during their migrations or, in small numbers, during winter: the Rusty and the Brewer's -- smaller than grackles and having shorter tails. Both have yellow eyes and, except in strong sunlight, appear to be all black. They are very similar but the Rusty nests in swampy woodlands far north, whereas the Brewer's is a prairie species.

The Starling, a chunky short-tailed distant relative of the blackbirds, walks with quick erratic steps. Introduced from Europe during the 1890's, it multiplied enormously and has become a pest from coast to coast. See Bulletin No. 140.


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