Contributing Editor Kenn Kaufman provides tips for identifying birds in every issue of BirdWatching. In June 2014, he tells what to look for to identify Yellow-billed Cuckoo — and to tell it from similar-looking Black-billed and Mangrove Cuckoos. He also offers this interesting description of the Yellow-billed’s unusual breeding habits:
Common Cuckoo is not the only brood parasite in the family. Some tropical American species, such as Striped Cuckoo and Pheasant Cuckoo, also lay eggs in the nests of other birds. And so do Yellow-billed and Black-billed Cuckoos — sometimes. While Yellow-billed Cuckoo normally raises its own young, it lays eggs in the nests of other birds surprisingly often. Other Yellow-billed or Black-billed Cuckoos are the most frequent hosts, but it has been known to target at least 10 other species, from robins to cardinals.
Local breeding populations of Yellow-billed Cuckoos can vary from year to year. They may concentrate where populations of tent caterpillars, cicadas, or other large insects have exploded. There’s some evidence that the cuckoos may lay more eggs during such times of abundance and may be more likely to leave the “extra” eggs in the nests of other birds.
Young Yellow-billed Cuckoos develop with amazing speed. The eggs hatch after only 9-11 days of incubation, and the young may be ready to leave the nest 8 days later, even though not full-grown then. (For comparison, a robin’s incubation period is 12-14 days, and the young usually fledge in about 13 days.) Obviously, rapid development is an advantage for a brood parasite, since the cuckoo’s egg is laid later than those of the host, and the young bird must catch up to be fed by the foster parents. — Kenn Kaufman
About Kenn Kaufman
Kenn Kaufman is naturalist, artist, conservationist, speaker, and author of many books, including the Kaufman Field Guide series and the beloved memoir Kingbird Highway. In August 2013 he was elected a Fellow of the American Ornithologists’ Union. His column “ID Tips,” featuring the photographs of Brian E. Small, appears in every issue of BirdWatching. The article above is an excerpt of a column that ran in our June 2014 issue. Subscribe.