The Yellow-billed Cuckoo is a medium-sized bird native to North America. Its scientific name is Coccyzus americanus. This cuckoo gets its name from its predominantly yellow lower mandible.
The Yellow-billed Cuckoo has experienced significant population declines in the past few decades due to habitat loss and degradation. As a result, the U.S. Fish and Wildlife Service listed the western distinct population segment of the Yellow-billed Cuckoo as threatened under the Endangered Species Act in 2014. The listing provides protections for the species in the western United States.
Background on the Yellow-billed Cuckoo
The Yellow-billed Cuckoo is a neotropical migrant bird, breeding in North America and wintering in South America. Its breeding range extends from southern Canada to the Greater Antilles and northern Mexico. The western population of the cuckoo breeds west of the Rocky Mountains from British Columbia to New Mexico and winters primarily in South America. The eastern population breeds east of the Rockies and winters in northern South America.
The Yellow-billed Cuckoo measures around 30 cm (12 inches) in length and weighs about 60 grams (2 ounces) on average. Its wingspan is around 13 inches. The bird has blue-gray upperparts and white underparts. As the name suggests, the lower half of its bill is yellow. The bird’s tail feathers are boldly patterned black and white underneath.
Habitat
The Yellow-billed Cuckoo inhabits dense, low-elevation riparian woodlands and floodplain forests dominated by willows, cottonwoods, and other small trees and large shrubs. It nests in thickets and patches of dense scrub vegetation. The cuckoo’s habitat has declined dramatically due to clearing of riparian forests for agriculture, urban development, river flow management, and invasive species. Loss of the cuckoo’s breeding habitat is considered the primary threat to the species.
Feeding
The cuckoo mostly eats insects, especially caterpillars and beetle larvae. It occasionally eats small lizards, frogs, eggs and young birds, seeds, and fruits as well. The Yellow-billed Cuckoo often raids nests of other birds to eat eggs and nestlings. It typically catches prey by gleaning foliage or making short flights.
Breeding
The Yellow-billed Cuckoo breeds between late June and July across most of its range. It builds a flimsy stick nest in the fork of a bush or low tree. The female lays 2-5 light blue eggs which she incubates alone for about 11 days. Both parents feed the young, which leave the nest at 10-11 days old but remain dependent on the parents for another 3-4 weeks.
Population Declines and ESA Listing
Once considered common, the Yellow-billed Cuckoo has experienced substantial population declines since the 1960s. Breeding Bird Survey data indicates an annual decline of about 3% per year between 1966 and 2013 throughout the cuckoo’s U.S. range. Scientists estimate the total breeding population has declined by 50-75% since the 1960s.
The primary causes of the cuckoo’s decline are habitat loss, degradation, and fragmentation. Conversion of native riparian woodlands for agriculture and development has severely reduced nesting habitat across much of the species’ range. River flow management, invasive species like tamarisk, and livestock grazing have also degraded the quality of remaining habitats.
In 2001, the Yellow-billed Cuckoo was designated as a Bird of Conservation Concern by the U.S. Fish and Wildlife Service. This status highlighted the species’ declining populations and prompted increased conservation attention. In 2014, the Service listed the distinct population segment of the cuckoo west of the Rocky Mountains as a threatened species under the Endangered Species Act.
Reasons for ESA listing
The western Yellow-billed Cuckoo was listed as threatened based on the following evidence of its declining populations:
– Breeding Bird Survey data showed an annual population decline of 2.7% from 1968 to 2011 throughout the western U.S.
– The estimated population in the western U.S. declined from roughly 120,000 to 30,000 breeding pairs from the 1960s to the early 2000s.
– The breeding range contracted by about 50% over the same time period.
– Most remaining western populations were small and isolated.
– Remaining habitat was highly fragmented and degraded.
This dramatic decline in population, breeding range, and habitat quality prompted the threatened listing. The eastern population was not listed because it did not meet the requirements for federal protection under the ESA at the time.
Protections under the ESA
By listing the species as threatened, the U.S. Fish and Wildlife Service extended the following protections to the western Yellow-billed Cuckoo under the Endangered Species Act:
– Prohibited take of the species, including harming or killing cuckoos, destroying nests, or collecting eggs.
– Required federal agencies to consult with the Service to ensure any activities they authorize, permit, or fund will not jeopardize the species.
– Designated critical habitat protection for 208,973 acres across Arizona, California, Colorado, Idaho, Nevada, New Mexico, Texas, Utah, and Wyoming.
– Authorized development of a recovery plan outlining actions needed to improve the species’ status so it no longer requires ESA protection. Published in 2020, the recovery plan aims to stabilize populations, restore habitat, and build resilience against climate change impacts.
– Provided opportunities for landowner partnerships to voluntarily conserve cuckoo habitat on their lands.
– Prohibited sale or trade of the species across state lines.
Recap – Key ESA Listing Details
– The Yellow-billed Cuckoo’s western U.S. population was listed as threatened under the ESA in 2014. The eastern population was not listed.
– Population declines of over 50% since the 1960s due to habitat loss prompted the listing.
– Critical habitat protection was designated for 208,973 acres across 9 western states.
– The listing provides protections from take and supports habitat conservation partnerships.
– A recovery plan aims to improve habitat and stabilize populations so ESA protection is no longer needed.
Ongoing Conservation Efforts
Listing under the Endangered Species Act provides an important safety net by prohibiting take and requiring habitat protections. However, recovering the Yellow-billed Cuckoo requires proactive conservation efforts as well. Ongoing efforts include:
Habitat Restoration
– Removing invasive species like tamarisk and Russian olive and replanting native trees and shrubs.
– Restoring natural river flows where feasible to support healthy riparian areas.
– Working with landowners to protect and improve cuckoo habitat through easements, safe harbor agreements, and financial incentives.
Wildfire Management
– Managing fuel loads and vegetation to reduce severity of fires in riparian areas.
– After wildfires, rehabilitating burned habitat by replanting native vegetation.
Captive Breeding and Release
– Rearing cuckoo chicks in captivity and releasing them into suitable habitat to boost wild populations.
– Between 2014 and 2019, 194 captive-reared cuckoos were released in Arizona and New Mexico.
Population Monitoring
– Tracking populations and habitat use through surveys, banding, and telemetry studies to guide effective conservation.
– Updating recovery targets and habitat management as new information emerges.
Outlook for the Yellow-billed Cuckoo
While ongoing conservation efforts are critical, the overall outlook for the Yellow-billed Cuckoo remains concerning. Some key reasons include:
– The human population in the Southwestern U.S. is projected to continue growing, increasing pressures on limited water resources and riparian habitats.
– Climate change will likely intensify droughts and wildfires, further stressing habitats.
– Full recovery would require large-scale restoration along thousands of miles of western rivers that is extremely challenging to achieve.
– Loss of wintering grounds in South America also needs to be addressed.
– There are significant funding constraints for implementing habitat projects on public and private lands.
Without major interventions, scientists estimate a high likelihood of continued declines or even extirpation of local populations. Preventing extinction and recovering the species to sustainable levels will require substantial, sustained support for habitat conservation backed by policy protections. Partnerships with landowners and water users will also be key.
Conclusion
The Yellow-billed Cuckoo was once abundant across North America, but habitat destruction has driven the western population dangerously close to extinction. Listing under the ESA in 2014 was critical to preventing collapse, but substantial efforts are still needed to restore and protect riparian areas. Addressing regional water management and working with partners on public and private lands offer hope for recovering cuckoo populations. But given ongoing pressures, the imperiled western cuckoo will likely require Endangered Species Act protections for the foreseeable future. Only through continued habitat and population monitoring and adaptive management can we ensure this unique species persists for future generations.