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.