U.S. Fish & Wildlife Service

Sacramento Fish & Wildlife OfficeServing the people, conserving the fish, wildlife, and plants of California

A Unit Of The Pacific Southwest Region

Species Information

Photo of Yellow Billed Cuckoo

Photo Credit: Mark Dettling / USFWS

Western Yellow-billed Cuckoo

Coccyzus americanus

Basic Species Information




The yellow-billed cuckoo (western distinct population segment) is a medium-sized bird of about 30 cm (about 12 inches) in length, and weighing about 60 g (about 2 ounces).

Plumage is grayish-brown above and white below, with red primary flight feathers. The tail feathers are boldly patterned with black and white below. The legs are short and bluish-gray. Adults have a narrow, yellow eye ring. Juveniles resemble adults, except the tail patterning is less distinct, and the lower bill may have little or no yellow.

On the cuckoo’s feet, two toes point forward and two point backwards. Most other birds have three pointing forward and one back. Feathers make up almost half of the yellow-billed cuckoos body weight.

The yellow-billed cuckoo is a member of the avian family Cuculidae. Some ornithologists have separated the species into eastern and western subspecies, which is a controversial distinction. However, the listed western population is a distinct vertebrate population segment.


Caterpillars and katydids are what cuckoos like to eat most, but they’ll catch tree frogs, cicadas, and grasshoppers to use as fast food for their young.

Learn more at http://bna.birds.cornell.edu/bna/species/290/articles/foodhabits


Yellow-bill cuckoos use a variety of riparian habitats. Cottonwood and willow trees are an important foraging habitat in areas where the species has been studied in California.

Western yellow-billed cuckoos appear to require large blocks of riparian habitat for nesting. Along the Sacramento River in California, nesting yellow-billed cuckoos occupied home ranges which included 25 acres (10 hectares) or more of riparian habitat. Another study on the same river found riparian patches with yellow-billed cuckoo pairs to average 99 acres (40 hectares). Home ranges in the South Fork of the Kern River in California averaged about 42 acres (17 hectares)


Western yellow-billed cuckoos breed in large blocks of riparian habitats (particularly woodlands with cottonwoods and willows). Dense understory foliage appears to be an important factor in nest site selection. Clutch size is usually two or three eggs. Development of the young are very rapid, with a breeding cycle of 17 days from egg-laying to fledging of young.

Yellow-billed cuckoos usually raise their own young, but have laid eggs in nests of at least 11 different kinds of birds. Most cuckoo pairs are monogamous, but about 30% of nests have unrelated helper males also feeding the young.

On day five or six, the nestling’s feathers burst out of their sheaths and the cuckoo chicks become fully feathered in just two hours. Most young cuckoos leave the nest on day 6. They can’t fly yet, but climb through the canopy.


The breeding range of the yellow-billed cuckoo formerly included most of North America from southern Canada to the Greater Antilles and northern Mexico. In recent years, the species' distribution in the west has contracted. The northern limit of breeding in the coastal states is now in Sacramento Valley.

The species overwinters from Columbia and Venezuela, south to northern Argentina. The extent to which yellow-billed cuckoos nesting in different regions of North America mingle during migration, or while overwintering, is unknown.


Principal causes of riparian habitat losses are conversion to agricultural and other uses, dams and river flow management, stream channelization and stabilization, and livestock grazing. Available breeding habitats for yellow-billed cuckoos have also been substantially reduced in area and quality by groundwater pumping, and the replacement of native riparian habitats by invasive non-native plants, particularly tamarisk.

Much of the dramatic decline of the yellow-billed cuckoo in California has been directly attributed to breeding habitat loss from clearing and removal of riparian forest for agriculture, urban development and flood control.

Overuse by livestock has been a major factor in the degradation and modification of riparian habitats in the western United States. The effects include changes in plant community structure and species composition, and relative abundance of species and plant density.


When landscaping your yard plant native trees like cottonwoods and willows, which support the cuckoo's insect prey. Avoid using pesticides on your landscaping as many brands kill the caterpillars on which the cuckoo depends. Keep your cat inside. Cats kill millions of birds per year. Even well-fed cats kill birds. It is just their nature to hunt. Living indoors is also much safer for the cats themselves.

Whenever you go to natural areas, observe any signs telling you how to protect wildlife and plants.

Last updated: November 30, 2017