After waiting more than 15 years for the federal government to agree that it needs protection, the western population of the yellow-billed cuckoo will be listed as Threatened Friday under the U.S. Endangered Species Act.
In a decision to be published Friday, the U.S. Fish and Wildlife Service has ruled that the small, strikingly patterned bird (Coccyzus americanus) is at risk of becoming endangered throughout its range in the western U.S., due to threats to the riverside forests and groves the cuckoo relies on as summer breeding habitat.
Those riparian forests are threatened by agriculture, hydrological changes due to dam building and water diversion, and an influx of invasive exotic plants, as well as the omnipresent threat of a warming, drying world.
Yellow-billed cuckoos are more common in the eastern United States: the rule lists only those birds with summer breeding ranges west of the Continental Divide, west Texas, and the Chihuahuan Desert in Mexico.
In addition to threats to their breeding habitat in the U.S., the birds are also subject to threats in their migration and winter ranges, including exposure to DDT in farmers' fields in Mexico and other countries where the pesticide has not been banned. The cuckoos are especially sensitive to pesticide poisoning because of their diet: they specialize in caterpillars that often emerge in large numbers, causing farmers to break out the sprays. When the cuckoos eat the caterpillars, they ingest any pesticides sprayed on those caterpillars.
The listing comes as the result of an October 2013 proposal to consider the western population for protection under the ESA, but the yellow-billed cuckoo's history with the Endangered Species process goes back way further than a year ago. Environmentalists first started seeking ESA protection for the cuckoo in the late 1980s, but were turned down in 1988 due to disagreements over whether the birds the groups wanted protected were genetically distinct from other yellow-billed cuckoos.
That dispute is closer to resolved, with many authorities suggesting that the distinct genetic makeup of the western cuckoo population may merit declaring that population a subspecies. Regardless, USFWS in 2001 responded to a 1998 petition to list the cuckoo by issuing a "warranted but precluded" ruling. That means the agency agreed the cuckoo needed protection, but that it wasn't as high a priority as some other species.
The cuckoo still had that warranted but precluded status in 2011, when USFWS and the Center for Biological Diversity reached a legal settlement in which the agency agreed to process some of its backlog of Endangered Species Act decisions on more than 750 species. The western yellow-billed cuckoo was one of those species.
CBD was quick to applaud the cuckoo's protection on Thursday. "Yellow-billed cuckoos were once common along rivers all over the West, but because of our poor treatment of western rivers, they're now found in just a handful of places," said CBD's Noah Greenwald. "With just a little more care, we can restore the rivers the cuckoo needs to survive, benefiting not just this unique songbird, but hundreds of other plants and animals and people too."