Yellow-billed Cuckoo | Coccyzus americanus

Voice

A wooden, knocking ka-ka-ka-ka-kow-kow-kowlp-kowlp, slowing and dropping towards the end; also a drawn-out, hollow cooo, repeated at long intervals. Heard on the breeding grounds in summer; migrants are mostly silent.

Identification

26–30 cm, about half of it tail. The upperparts are plain grey-brown, the underparts pure white without markings. The bill is slightly curved; the upper mandible is black, the lower largely yellow. A narrow yellow ring surrounds the eye. In flight a rufous patch in the primaries stands out, often visible on a perched bird as a rusty edge to the folded wing. The underside of the tail is black with large white spots at the feather tips. The sexes are alike; young birds have less yellow on the bill and a less distinct tail pattern.

Confusion species

Black-billed Cuckoo Coccyzus erythropthalmus, also a passage migrant, has an all-dark bill, a red eye-ring in adults, at most a hint of rufous in the wing and narrow white tips on the underside of the tail. Mangrove Cuckoo Coccyzus minor also has a yellow lower mandible and large white tail spots, but has a black eye mask, ochre underparts and no rufous in the wing. The rare Pearly-breasted Cuckoo Coccyzus euleri lacks the rufous in the wing.

Habitat

It breeds in riparian woodland, especially with willows and cottonwoods, in dry deciduous forest and in wooded scrub. On migration in almost any forest, forest edges, scrub, mangroves, parks and gardens with trees, mainly in the lowlands. It forages slowly and hidden in the foliage, taking large insects, especially caterpillars, as well as cicadas and grasshoppers. The nest is a loose, flat platform of twigs in a bush or tree; the species incubates its own eggs, although it occasionally lays an egg in another bird's nest.

Range and movements

Breeds from May to September in northern Mexico: in southern Baja California Sur, in Sonora, Chihuahua, Sinaloa and Durango, and in the north-east in Coahuila, Nuevo León and Tamaulipas, locally further south. As a passage migrant throughout the guide area, most numerous along the Gulf coast of Veracruz, on the Yucatán Peninsula, in Belize and in the Caribbean lowlands of Central America to Panama; scarcer inland and on the Pacific side. It hardly winters in the guide area. Outside the guide area it breeds from southern Canada through the United States and winters in South America, south to northern Argentina.

• Summer visitor (c. Apr–Sep)
• dark = core range, pale = thinly spread

How and when to look

The best chance is during migration, especially in September and October and again from late April into May, in woods and forest edges along the Gulf and Caribbean coasts, such as on the Yucatán Peninsula. A bird sitting still in dense foliage is often noticed only when it flies off and shows the rufous in the wing. In northern Mexico breeding birds give themselves away in summer by their knocking call.

Conservation status

Globally not threatened, but it has declined sharply in western North America; the western population, to which the breeding birds of north-western Mexico are also assigned, has been listed as threatened in the United States since 2014. As a passage migrant locally numerous in the guide area.

Scientific name

Coccyzus americanus | (Linnaeus, 1758)

Linnaeus described the species in 1758 as Cuculus americanus; because it was later moved to another genus, the author and year stand in brackets. The genus Coccyzus was introduced in 1816 by Vieillot. Coccyzus is Greek, from kokkuzō 'to cry cuckoo', after the cuckoo's call. americanus is Latin for 'American'. The specimen the first description was based on came from South Carolina, United States.