Nature Bulletin No. 346-A   May 24, 1969
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

****:CUCKOOS AND COWBIRDS

The European Cuckoo has long been famous for two peculiarities; the 
call of the male, imitated by innumerable "cuckoo clocks", and the 
parasitic habits of the females which, like our native Cowbird, 
invariably lay their eggs in the nests of other birds. It was as prominent 
in the mythology and writings of the ancient Greeks as it is in the verses 
of the English poets. It is twice mentioned in the Bible in the laws of 
Moses which prohibited the Israelites from eating its flesh.

Our American cuckoos are wholly unlike their European and African 
cousins in most respects. The Yellow-billed Cuckoo, a California 
variety of it, the Black-billed Cuckoo, and two species which range as 
far north as southern Florida, are not hawklike but resemble a slender 
pigeon with a longer neck and tail. Like most birds, they almost always 
build their own nests and faithfully rear their young. Other American 
members of this peculiar family are the Road-runner or Ground 
Cuckoos, and the black Ani, or Tick Bird, found in southern Texas.

The yellow-billed cuckoo, or Rain Crow, is a slender graceful bird 
about 12 inches long, dull brown above and grayish white below. It 
differs from the black billed cuckoo in that the lower part of the long 
curved bill is yellow instead of black, the under sides of its wings are 
reddish, and its long black tail feathers are conspicuously marked with 
large white spots. Although fairly common throughout eastern United 
States, it keeps so well hidden among the foliage of orchards, or trees 
and thickets near wet low places, and flies so furtively from tree to tree, 
that it is rarely seen. Farmers believe that rain is coming when they hear 
its peculiar call: a rapid series of guttural clucks with a hollow wooden 
sound, slowing toward the end, like, "ka ka ka ka kowp - kowp - kowp - 
kowp". Its nest is a flimsy platform of twigs, lined with a few rootlets, 
in a bush or small tree. When hatched, the young cuckoo has a naked 
coal-black leathery skin like a young kingfisher, but within six days it 
bristles with quill-like tubes which, when ready to leave the nest, it 
quickly plucks off to release the feathers.

The black-billed cuckoo has about the same range and habits, although 
it seems to be fonder of extensive woodlands and more active at night. 
Its call is a fast rhythmic even-pitched "cu cu cu, cucucu, cucucu". Both 
species are valuable because, like the European cuckoo, they eat 
enormous numbers of canker worms and caterpillars, especially the 
hairy or spiny kinds that most birds avoid, such as the destructive tent 
caterpillars, fall webworms and tussock moth larvae.

The European cuckoo has apparently become unable to rear its own 
young. The female sneaks into the nest of some smaller bird when she is 
absent, destroys or carries away at least one egg, and lays one of her 
own. She may lay 20 or more eggs in as many nests -- always choosing 
the same kind of bird. Different strains of the European cuckoo 
specialize on different species. When it hatches, the young cuckoo 
destroys, or pushes out of the nest, all other eggs and any chicks already 
hatched and settles down to gobble the food brought by its industrious 
foster parents.

We have only one such parasitic bird in the United States, the Brown-
headed Cowbird which used to follow the great herds of Bison and now 
attends our cattle. The female lays 4 or 5 eggs, a day apart, each in a 
different nest. Robins and catbirds destroy them, yellow warblers cover 
them with a new nest, but most birds tolerate them. The young cowbird 
hatches quickly, usually gets rid of the other eggs and nestling, eats 
greedily, grows fast, and leaves in about 10 days.

These cuckoos and cowbirds are fast guys with an egg!