Wing long and pointed, third quill longest and exceeding the secondaries in the closed wing by almost half the length of the wing. The first primary is about two-thirds the length of the wing. Tail shorter than wing, graduated, the outer feathers falling short of the middle pair by one-fourth to one-third the length of the tail. Bill moderate. In adults the upper plumage is almost uniform dark ashy or brown, the chin and throat ashy, abdomen white barred with black; the wings barred on the inner webs. The young undergo two or three changes, one phase being chestnut above barred with dark brown.
The true Cuckoos have a wide range, being found in Europe, Asia, Africa, and Australia, and comprise about nine species, of which four inhabit the Indian area.
Key to the Species.
Wing 8 to 9 in., no subterminal black band on tail; edge of wing mixed white and brown. ……………….C. canorus, p. 205.
Wing 6.5 to 7.8 ; edge of wing white……………….C. saturatus, p. 207.
Wing 5.7 to 6.1; edge of wing ashy……………….C. poliocephalus, p. 208.
Wing 7.5 to 8.5 ; a subterminal black band on tail……………….C. micropterus, p. 210.
Cuckoos are birds of swift flight and peculiar habits. All have resonant call-notes, distinctive of the particular species. The true Cuckoos are more or less migratory; they feed chiefly on caterpillars and soft insects, and, as is well known, do not pair, but indulge in promiscuous intercourse, and the females deposit their eggs in the nests of other birds *. The female Cuckoo sometimes, at all events, perhaps always, lays her egg on the ground and conveys it in her mouth to the nest selected. Some of the eggs already in the nest are often broken, whether intentionally or by accident is not quite clear, but it is certain that the young Cuckoo when hatched ejects from the nest the callow young of its foster-parents, and is fed by the latter until full-grown. When two Cuckoo's eggs are laid in the same nest, the stronger young Cuckoo turns out the weaker.