Conserving the Nature of America
Service Completes Initial Reviews on Petitions to List the Oregon Vesper Sparrow and Recently-Discovered Toad, and Delist the Yellow-Billed Cuckoo

June 26, 2018


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Telephone: 703-358-2220

The U.S. Fish and Wildlife Service (Service) has completed initial reviews on petitions to list under the Endangered Species Act (ESA) the Dixie Valley toad in Nevada and the Oregon vesper sparrow, and to delist the Western Distinct Population Segment of yellow-billed cuckoo. The Service found that all three petitions presented substantial information and will begin in-depth, scientifically rigorous reviews to determine whether the petitioned actions are warranted.

The Dixie Valley toad is a recently discovered toad species that flaunts flecks of gold on an olive background.  The toad is only found within four isolated spring-fed wetlands in Dixie Valley, Nevada. The arid region, about 100 miles east of Reno, has very limited aquatic resources.  Possible threats to the toad include habitat loss, decreases in spring discharge, changes in water temperature, groundwater extraction, potential impacts from geothermal energy development, chytridiomycosis fungus and predation by the invasive American bullfrog.

The Oregon vesper sparrow is a subspecies of the vesper sparrow, a migratory grasslands-dependent bird.  The subspecies has a restricted breeding range within a few areas in Washington, Oregon, and northwestern corner of California and a winter range that is limited to a few areas in California.  This bird’s current overall population size is small, estimated at around 3,000 individuals.  Possible threats include loss or degradation of breeding, migratory stopover, and wintering habitats.

The yellow-billed cuckoo occurs in North America across the continental United States and parts of British Columbia and Mexico, and winters in Central and South America. The currently listed Western Distinct Population Segment (DPS) of this bird is the western yellow-billed cuckoo, which generally occurs in the area west of the Rocky Mountains, from British Columbia to Mexico.

The Federal Register docket numbers and links for the substantial findings in this batch are:



Docket Number

Docket link

Dixie Valley toad

Only in Churchill County, Nevada


Oregon vesper sparrow

Washington, Oregon and California


Yellow-billed cuckoo

Continental United States, and parts of Mexico and British Columbia



The notice for the above findings will be available in the Federal Register Reading Room on June 26, 2018 at by clicking on the 2018 Notices link under Endangered and Threatened Wildlife and Plants.

Substantial 90-day findings represent one step in a rigorous process by which the Service determines whether or not a species warrants a change in listing status under the ESA. Substantial petition findings only require that the petitioner provide adequate information that the change in listing status may be warranted. This then triggers a thorough, scientifically rigorous species status assessment. For more information on the ESA listing process, including 90-day findings and status reviews, please go to

As the Service begins its in-depth review of these three species, it is important that the agency has the best and most up-to-date information possible to inform its decision-making process, including any new information concerning the status of or threats to this species or its habitat. The public can play a role by sending pertinent scientific and commercial data and other information for us to consider in the status review. Complete instructions for submitting comments are provided in the Federal Register notice.

Information contained in older news items may be outdated. These materials are made available as historical archival information only. Individual contacts have been replaced with general External Affairs office information. No other updates have been made to the information and we do not guarantee current accuracy or completeness.

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