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! 

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