At every stage of its complex life cycle there are hurdles. Here in the UK some of the host species are in decline, some important food sources such as caterpillar moths are also in steep decline and there is the constant threat of habitat loss. Outside of the UK weather pattern changes may be affecting their migration and food shortages in their wintering grounds.
Each species of Old World cuckoo has its own unique pattern of parasitism, and different species choose different host species for their eggs. The cuckoo is referred to in the Bible, by Aristotle and Pliny, in mythology, and in English poetry. Its nesting habits have given us the word cuckold, and its simple but musical song, which gives it its name, was used by Beethoven in his Pastoral Symphony and is also imitated in the cuckoo clock.
The American cuckoos look like attenuated pigeons; they are not parasitic and build flimsy nests of twigs. Typical are the black-billed and yellow-billed (Coccyzus americanus) cuckoos, known for their low, chuckling call notes. They frequent and breed at the edges of deciduous woodlands, either species tending the young of the other. These birds are valued as destroyers of harmful insectsparticularly the tent caterpillar, which few other birds will eat. There are also western and southern species.
Most gregarious of the cuckoos are the anis of the American tropics. The groove-billed ani, from 12 to 14 in. (3035 cm) long, has black plumage with a faint purple gloss. Anis nest colonially, several females together laying as many as 25 eggs in the same nest, and they may breed at any time of the year.
Geographic Variation Presently considered monotypic; however, there have been 2 subspecies described: americanus in eastern North America andoccidentalis in the Southwest. The differentiation of these taxa is weak and limited in the contact zone.
Similar Species The yellow-billed cuckoo most closely resembles the black-billed cuckoo, but it is distinguished by the yellow orbital ring, rufous primaries, more prominently white-tipped tail, and the yellow lower mandible. Some calls, however, are quite similar.
Voice Call: a rapid staccato kuk-kuk-kuk that usually slows and descends into a kakakowlp-kowlp ending; sounds hollow and wooden.
Status and Distribution Common in eastern North America, becoming increasingly rare and local in much of the West. Breeding: open woodlands with dense undergrowth, riparian corridors, and parks. Southwestern populations increasingly limited to riparian corridors.