The yellow-billed cuckoo in the western United States was accorded candidate status in July 2001. An annual review was conducted in December 2007.

Historical Status and Current Trends

Historically, the yellow-billed cuckoo bred throughout much of North America. Available data suggests that within the last 50 years the species' distribution west of the Rocky Mountains has declined substantially. Loss of streamside habitat is regarded as the primary reason for the population decline. The species was probably never common in Oregon. Historical records for the state show that breeding cuckoos were most often sighted in willow bottoms along the Willamette and Columbia Rivers; there are few records of cuckoo sightings in eastern Oregon.

Habitat Associations

Western yellow-billed cuckoos breed in dense willow and cottonwood stands in river floodplains.

Description and Life History

The yellow-billed cuckoo is a medium sized brown bird, about 12 inches long and weighing about two ounces. The bird's most notable physical features are a long boldly patterned black and white tail and an elongated down-curved bill which is yellow on the bottom. Yellow-billed cuckoos are migratory; historically, cuckoos arrived in Oregon in mid-May and flew south to their wintering grounds in September. Although many species of cuckoos are brood parasites (laying their eggs in other birds' nests), the yellow-billed cuckoo usually builds its own nest and raises its own young. The distinct call of the cuckoo has been described as sounding like "cow, cow, cow, cow, cow, cow..." a series of clucks that become slower and run down the scale at the end. The yellow-billed cuckoo is sometimes called the raincrow or stormcrow, because it often calls before a rainstorm.

Food

The bird primarily eats large insects including caterpillars and cicadas and, occasionally, small frogs and lizards. Breeding coincides with the emergence of cicadas and tent caterpillar.

Reasons for Decline

Available data suggests that the yellow-billed cuckoo's range and population numbers have declined substantially across much of the western United States over the last 50 years. In Oregon, cuckoos, although never common, have become even more rare with the loss of floodplain forests along the Willamette and Columbia Rivers. The last confirmed breeding records in Oregon were in the 1940s. Most of the recent records of cuckoos are from eastern Oregon at Malheur National Wildlife Refuge in Harney county, and from Malheur and Deschutes counties.

The greatest threat to the species has been reported to be loss of riparian habitat. It has been estimated that 90 percent of the cuckoo's stream-side habitat has been lost. Habitat loss in the west is attributed to agriculture, dams, and river flow management, overgrazing and competition from exotic plants such as tamarisk.

Conservation Measures

In 1998, we received a petition to list the western yellow-billed cuckoo as an endangered species. We concluded that the western yellow-billed cuckoo is a distinct population segment (DPS) of the yellow-billed cuckoo in North America. We determined that the western yellow-billed cuckoo DPS was warranted for listing, but was precluded by other higher priority listing actions, and we placed the species on our candidate list. We will conduct an annual review of the species' status, and may propose to list the species at a later date. We will encourage state and federal agencies as well as other parties to give consideration to the species in environmental planning. Activities which alter or destroy riparian habitat are of particular concern, including unmanaged cattle grazing that contributes to the loss of sub-canopy vegetation and cottonwood regeneration.

Links and References

U.S. Fish and Wildlife Service. 2001. 12-month finding for a petition to list the yellow- billed cuckoo (Coccyzus americanus) in the western continental United States. FR 66: 38611-38626.