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Center for Biological Diversity The Yellow-billed Cuckoo
(Coccyzus americanus)

The Yellow-billed cuckoo is also called the Raincrow or Stormcrow because its call heralds the coming of summer rains. This habit, combined with its beauty and ability to eat enormous quantities of defoliating caterpillars, has made the Yellow-billed cuckoo a popular bird in North America. Unlike European cuckoos, it rarely lays its eggs in the nests of other birds. It is a neo-tropical migrant which winters in South America. Before its precipitous decline, it summered and bred in most of the United States, southernmost Canada, and northern Mexico.

The yellow-billed cuckoo is at a critically low population level, not only in California, but in the northern Rocky Mountains, the Great Basin, and the Pacific Northwest as well.”
Gaines, D. and Laymon, S.A. 1984. Decline, status and preservation of the Yellow-billed Cuckoo in California. Western Birds 15:49- 80.

The cuckoo is one of the last neotropical migrants to arrive in North America and has very little time to build a nest, find a mate, lay its eggs and raise its young. To do so, it has evolved a unique nesting strategy. It is able to time its egg laying with outbreaks of insects (especially caterpillars) so that it has a rich food source for itself and its young. Its incubation/nestling period is the shortest of any known bird. Its egg develops rapidly, and at hatching is one the heaviest of all North American songbirds. This is because the chick will have very little rearing time before embarking on its transcontinental migration- it must complete much of its development while still in the egg and come out ready to go. The nestling are fledged from the nest 6-7 days after hatching, and are off to South America at three or four weeks of age.

Cuckoo Declines East & West

The Yellow-billed Cuckoo has declined precipitously throughout its range in southern Canada, the United States, and northern Mexico. It is nearly extinct west of the Continental Divide having disappeared from British Columbia in the 1920's, from Washington in the 1930's, from Oregon in the 1940's, and from northern-most California in the 1950's. It is extremely rare in the interior West. Its only remaining western "strongholds" are three small populations in California, scattered populations in Arizona (especially on the San Pedro River) and New Mexico (especially the Gila River), and an unknown number of birds in northern Mexico. Click here to see a map of the cuckoo's current and historic range in the West.

Though the cuckoo has faired better east of the Continental Divide, it is declining there rapidly as well, and will likely sink to western levels and eventual extinction if its habitat is not soon protected. According to Breeding Bird Survey data, Yellow-billed Cuckoos have suffered significant population declines in the last 33 years (1966-1999) in 14 of 29 eastern states with sufficient data to determine trends. The average decline was 54% for the 14 states, with some declines reaching 78 and 99%. The area and rate of decline is increasing over time: declines occurred in all 29 states between 1980-1996 and was statistically significant in 17. The average decline was 60% in this short, recent period. If the decline continues at its current rate for another 30 years, cuckoos will have declined by nearly 80% east of the Continental Divide between 1966 and 2026. If the current rate of decline continues for 100 years, cuckoos will be virtually if not completely extinct in large portions if not all of eastern North America. For a more detailed analysis of the breeding bird survey data, see the Center’s report Yellow-billed Cuckoo Breeding Bird Survey Trends 1966-1999.

The future of the Yellow-billed Cuckoo is uncertain. Populations are declining precipitously throughout its distribution ... Immediate conservation intervention is essential to ensure that the Raincrow continues to be heard calling among western cottonwoods.” Hughes, J.M. 1999. Yellow-billed Cuckoo (Coccyzus americanus). The Birds of North America, No. 418. The Birds of North America, Inc., Philadelphia, PA.

The cause of the cuckoo's demise is the same threat facing most endangered species- habitat loss. In the West, cuckoos are closely associated with broadleaf riparian (i.e. streamside) forests. Logging, cattle grazing, dams, water diversions, and water pumping have decimated the West's rivers and riparian forests, however, causing over a hundred birds, fish, amphibians, and mammals to be listed as federally endangered species. In most western states, 60-95% of the riparian forests have been destroyed. East of the Continental Divide, the cuckoo faces many of the same threats, but as the climate is generally more humid, it is able to tolerate greater levels of habitat destruction. Its decline in the East, therefore, was delayed, but is increasing rapidly.

Taking Action to Protect the Rain Crow

"By 1990, however, even though it had been decades since the Yellow-billed had been seen in areas where it was once common...the [U.S. Fish & Wildlife] Service switched it to Category 3B "candidate" status, indicating that it failed to meet the legal definition for [ESA] listing. This appears to have been a political rather than a scientific decision."
P.R. Ehrlich, D.S. Dobkin, and D. Wheye. 1992. Birds in Jeopardy. Stanford University Press. Stanford, CA.

Recognizing that cuckoos would soon be extinct in the West if action was not taken, environmentalists filed a formal petition to list the cuckoo under the Endangered Species Act in California, Oregon, and Washington in 1987. Despite a recommendation to list the cuckoo as "endangered" from the West Coast region of the U.S. Fish & Wildlife Service, the petition was rejected because of political intervention by the Southwest region. More than one scientist lamented the decision as death knell of the Raincrow in the West.

In order to get cuckoo protection back on track, the Center completed a comprehensive review of its status in 1997. In 1998 the Center filed a updated ESA petition with the U.S. Fish & Wildlife Service. This petition called for listing cuckoos west of the Continental Divide as either a subspecies (i.e. the Western Yellow-billed Cuckoo) or as a population which is geographically, morphologically, behaviorally, and ecologically distinct from cuckoo's east of the divide. In addition, the petition asked the Fish & Wildlife Service to list the entire species in North American because of ongoing declines east of the continental divide. Joining the Center on the petition where: Maricopa Audubon Society, Tucson Audubon Society, Huachuca Audubon Society, White Mountain Audubon Society, White Mountain Conservation League, Wildlife Damage Review, Sky Island Alliance, San Pedro 100, Zane Grey Chapter of Trout Unlimited, T and E Inc., Biodiversity Legal Foundation, Environmental Protection Information Center, Sierra Nevada Alliance, Wetlands Action Network, Rangewatch, Oregon Natural Desert Association, ONRC Fund, Klamath-Siskiyou Wildlands Center, Southern Utah Wilderness Alliance, Friends of Nevada Wilderness, and the Toiyabe Chapter of the Sierra Club, Wild Utah Forest Campaign, Sierra Nevada Alliance, Toiyabe Sierra Club.

"The best available scientific information indicates that cuckoo populations are declining at an alarming and increasing rate throughout much of North America .... Endangered Species Act listing of the cuckoo, as a species, subspecies, or distinct population segment is necessary to arrest the current trajectory toward extirpation in large portions of the species’ range."
Letter from twenty-two scientists to the U.S. Fish & Wildlife Service, April 14, 2000

When the Fish & Wildlife Service refused to process the petition, the Center filed suit to obtain a review and decision by the Service. On 2-17-00, the Fish & Wildlife Service published an initial finding that ESA protection may be needed for western cuckoos, either as subspecies or a unique population. Incredibly, however, it cast doubt on whether the extinction of the cuckoo from all of western North America would be biologically significant. If it concludes that it is not significant, the Service will refuse to list the western population. Just as bad, the Service refused to even consider listing the entire species as endangered throughout North America. Political considerations are once again influencing the agency's agenda. The fear of angering powerful industry and development interests is eclipsing the agency's commitment to reversing the decline of American songbirds.

Scientists Support Protection but Citizen Action is Necessary

A broad array of scientists have supported listing both the western subspecies and the entire species. On 4-14-00, twenty-two scientists including Dr. Peter Raven of the Missouri Botanical Gardens, Dr. John Terborgh of the Duke University Center for Tropical Conservation, Dr. Reed Noss, President of the Society for Conservation Biology, Dr. David Dobkin of the High Desert Ecological Research Institute, Janice Hughes of the Royal Ontario Museum, Dr. Thomas Smith of the San Francisco State University Center for Tropical Research, Dr. Peter Stacey of the University of New Mexico, and Dr. Robert Ohmart of Arizona State University sent a letter to U.S. Fish & Wildlife Service asking that the cuckoo be listed as an endangered species. The most prominent cuckoo researcher in the western U.S., Dr. Stephen Laymon, prepared a lengthy report supporting the listing of the species and the subspecies. Other researchers conducted a genetic analysis determining that eastern and western populations have been separated for 410,000 to 460,000 years and likely warrant designation as separate subspecies.

Represented by Earthjustice, Center filed a second lawsuit against the U.S. Fish & Wildlife Service on 7-31-00 because the agency has already missed its next deadline for deciding whether to propose or deny ESA protection for cuckoo. The suit also asks a federal judge to order the agency to review the status of the entire species. The Center was joined in the suit by the Huachuca Audubon Society, Maricopa Audubon Society, ONRC Fund, Wetlands Action Network, Wildlife Damage Review, San Pedro 100, Southern Utah Wilderness Alliance, Friends of the River, Sky Island Alliance, Oregon Natural Desert Association, and Klamath Siskiyou Wildlands Center. Our 60-day notice of intent to sue provides a more detailed overview of the legal and biological issues than the legal complaint.

With a little bit of luck and a good deal of citizen organizing, science and moral integrity will prevail over political intervention, and the Yellow-billed Cuckoo and the riverside forests it depends on will begin the slow process of recovery. Overgrazing and excessive water pumping (especially on the San Pedro River) must stop, willows and cottonwoods must be replanted along ailing rivers and streams, invasive tamarisk trees must be removed, urban and agricultural sprawl must be controlled, and outdated dams must be removed. When this is done, we'll find the restored rivers are more inviting to humans and fish, as well as to Raincrows.

Other Center Actions to Protect Western Rivers, Deserts and Forests

The key to protecting the Yellow-billed Cuckoo is habitat protection. Over the last decade the Center has increased protection on a vast network of western streams, deserts and forests which will not only help the cuckoo, it will ensure enough habitat to protect thousands of species of birds, mammals, flower, reptiles, fish and amphibians. In the last decade, the Center has won protection for 121 species under the Endangered Species Act and the designation of 833,000 acres of land and 2,790 miles of river as federally protected “critical habitat". We have won proposals for the designation of another 68.8 million acres, including 1.81 million acres in California, 53.5 million acres in Alaska, and over 13.5 million in Arizona and New Mexico. By the end of 2001, we expect to have secured ESA protection for 129 species, 69.5 million acres of land, and over 4,000 miles of river. Though the Center's successes are unprecedented, so is the level of ecosystem destruction being wrought on the planet. In the long-run, we need to increase habitat protection a hundred fold to successfully protect and restore native biological diversity in the West.

List of Center Actions to Protect the Cuckoo


Petition to List Cuckoo as Endangered
USFWS 90-Day Finding that Listing May be Warranted in Western North America
60-day Notice of Intent to Sue For Delaying 12-Month Finding and Refusing to Consider Protection of Eastern Cuckoos
7-31-00 Lawsuit Filing to End Delay in Review of Western Cuckoos, and to Force Federal Review of Eastern Cuckoos


Historic vs. Current Distribution in West
Status in Southwest (NM Game & Fish)
Status in Southwest (USGS)
Status in California


Breeding Bird Survey Data


Status Review by Dr. Stephen Laymon Supporting Listing of Cuckoos in East and West
Letter by 22 Scientists Supporting Federal Protection of Cuckoos in East and West
Genetic Analysis Demonstrating Difference Between Eastern and Western Subspecies
Yellow-billed Cuckoo Breeding Bird Survey Trends 1966-1999
Editorial by Naturalist Susan Tweit


Center for Biological Diversity: Yellow-billed Cuckoo Breeding Bird Survey Trends 1966-1999
U.S. Geological Survey

U.S. Fish & Wildlife Service
Patuxent Wildlife Research Center
The Nature Conservancy


Animal Web
Taylor Road Middle School, GA
San Benito High Schoo, TX

Songs and Calls
John James Audubon Painting
International Postage Stamps
Song by Yellow-billed Cuckoo
Song about Yellow-billed Cuckoo

July 28, 2000

Center for Biological Diversity