Description ADULT Has dark gray-brown upperparts, least colorful on crown and darkest through eye. Rufous flight feathers are most obvious in flight. Underparts are otherwise whitish. Tail is long and wedge-shaped when spread; from above, central upper tail is reddish, while rest of tail is black, all feathers having striking white tips; from below, note striking, large white spots (feather tips) to otherwise black tail feathers. Bill is downcurved with yellow base to lower mandible. Note yellow eyering. JUVENILE Similar to adult, but less colorful and with less contrasting undertail pattern.
Dimensions Length: 10 1/2-12 1/2" (27-32 cm)
Habitat Common summer visitor (mainly May-Sep); winters in South America. Favors dense scrub and woodland, often beside rivers. Usually builds its own nest but occasionally lays eggs in nest of other species, notably Black-billed Cuckoo.
Observation Tips Easiest to see and hear shortly after arrival from migration in late spring.
Range California, Mid-Atlantic, Eastern Canada, Rocky Mountains, Southwest, Texas, New England, Plains, Great Lakes, Florida, Southeast, Northwest
Voice Utters a rapid ke-ke-ke-ke-keeooa-keeooa-keeooa.
Similar Species Mangrove Cuckoo C. minor (L 11-12 in), a Florida specialty, is also widespread in Caribbean. Compared to Yellow-billed, note the dark mask, orange-buff wash on belly and undertail coverts, lack of rufous in wings, and different (a descending series of karr-karr-karrÖ notes). Favors mangroves.
Discussion Unobtrusive, long-tailed woodland bird. Presence often detected by hearing its distinctive call. Feeds on caterpillars, often hairy ones. Sexes are similar.
Migration Info This is one of the latest U.S. arrivals in spring, and is also one of the first to leave; some individuals spend less than a month in the breeding territory. This is possible because of the extremely rapid development of the young: The entire breeding cycle, from egg laying to fledging of young, may be completed in as little as 17 days. Eastern populations reach the New England states in late May or early June, while western birds at the same latitudes may arrive two weeks later. This species has been nearly extirpated in California due to loss of riparian breeding habitat.