Western Yellow-Billed Cuckoo - Illustration by Bill Singleton

Western Yellow-Billed Cuckoo

Coccyzus americanus occidentalis


The western yellow-billed cuckoo (Coccyzus americanus occidentalis) is a long and slender bird with relatively short, dark legs. The plumage is grayish-brown on top and white below. The primary feathers on the wings are rufous (orange-brown) in color, and there is a bold, black and white pattern under the tail. The lower mandible on the bill is yellow. Juveniles, which hold their plumage well into the fall, have a much paler pattern on the tail; and the bill may show little to no yellow. The "song sounds hollow and wooden, a rapid staccato kuk-kuk-kuk that usually slows and descends to a kakakowlp-kowlp ending."1

In Arizona, the western yellow billed cuckoo will use streamside cottonwood, willow groves and large mesquite bosques for migrating and breeding. This species may be rarely observed as transient in desert and urban settings.2

The total range for C. a. occidentalis is quite large. It nests anywhere from southern Canada, south through the United States to the Florida Keys, central America and southern Baja California. This species winters in South America to central Argentina and Uruguay. In Arizona, the western yellow billed cuckoo can be found in the southern, central and extreme northeastern areas.2

Breeding often coincides with outbreaks of cicadas and tent caterpillars. This species may lay more eggs in good prey-abundant years with the extra eggs possibly laid in other birds' nests.2

The diet for the western yellow-billed cuckoos consists of hairy caterpillars, bird eggs, frogs, lizards, ants, beetles, wasps, flies, berries and fruit. The parents will feed their young by regurgitating insects.2

Both the male and female nest, often in willow or mesquite thickets, from 4­30 feet above the ground. The nest is a stick platform, thinly lined with leaves, mesquite and cottonwood strips, grass and catkins with a little depression to hold the eggs. The nest is well concealed by the surrounding foliage. The yellow-billed cuckoo will lay 3­4 unmarked, pale greenish-blue eggs. Incubation usually lasts 4­11 days with the eggs changing color to greenish-yellow. The young hatch out of the eggs synchronously. The male will feed the first fledgling, while the female will feed the remaining young until they leave the nest in 7­8 days.2

Due to general population declines in all areas, the western yellow-billed cuckoo is currently petitioned for listing under the Endangered Species Act. The Arizona Game and Fish Department currently listed the species as "State Threatened"3 and a "Wildlife of Special Concern."4

The Western Yellow-Billed Cuckoo in Pima County:
Small numbers of this species have been observed in riparian woodlands (Cienega Creek and San Pedro River corridors) and pecan groves (Santa Cruz River) in eastern Pima County. Protection and restoration of healthy riparian habitats is essential to the continued existence of this species in Pima County as well as the rest of the country.



1.Scott, S. editor. 1987. Field Guide to The Birds of North America, second edition. The National Geographic Society, Washington, D.C. pp. 236-237

2.Arizona Game and Fish Department. Unpublished Abstract, Heritage Data Management System (HDMS). April 1999

3.Arizona Game and Fish Department. 1996. Wildlife of Special Concern in Arizona. p. 28.

4.Arizona Game and Fish Department. 1988. Threatened Native Wildlife in Arizona. p. 1



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