Pacific Southwest Region
California, Nevada and Klamath Basin

Service Determines Ashy Storm-Petrel Does Not Warrant Protection Under the Endangered Species Act

Oct 21, 2013

Oct. 21, 2013

Contact: Steve Martarano, (916) 930-5643,

Service Determines Ashy Storm-Petrel
Does Not Warrant Protection Under the Endangered Species Act

The U.S. Fish and Wildlife Service announced today it has completed a status review of ashy storm-petrel, a seabird that lives off the California coast, and concluded it does not warrant protection under the Endangered Species Act (ESA). The Service made this finding after a thorough review of all the available scientific and commercial information regarding its status and threats to the species.

The Service has determined that population trend data for ashy storm-petrel indicates that the species is currently undergoing natural population fluctuations and that the species is not in a long-term decline. The species report revealed that the primary stressors for the ashy storm-petrel are burrowing owl predation and western gull predation on Southeast Farallon Island, which were found to have a slight to moderate impact on the ashy storm-petrels located there. The Service determined that these threats do not rise to the level of warranting listing under the ESA because this predation may reduce the numbers of ashy storm-petrels at Southeast Farallon Island, but not to a point that the overall status of the species would be affected.  In addition, the historical range for the ashy storm-petrel has remained the same, indicating there has not been a loss in the range of the species over time.

Confirmed breeding locations for ashy storm-petrels have been identified at 32 locations (on islands and offshore rocks) from Mendocino County, California, south to the Todos Santos Islands, west of Ensenada, Baja California, Mexico. More than 90 percent of the species breeds in two population centers at Southeast Farallon Island and the following California Channel Islands: San Miquel, Santa Cruz, Anacapa, Santa Barbara, Santa Catalina, and San Clemente. At-sea observations of ashy storm-petrels south of Islas San Benitos, Mexico, are unusual; most observations of the species are off the coasts of California and Baja California, Mexico. Ashy storm-petrels occur at their breeding colonies nearly year-round and occur in greater numbers from February through October.

The ashy storm-petrel is a dark smoke-gray, medium-sized bird with long slender wings, a long forked tail, and webbed feet. It has a relatively short neck, large puffy head and small bill. The bill, legs, and feet are black. It can be distinguished from its close relative Leach's storm-petrel by color, as ashy storm-petrel is almost entirely black while Leach's storm-petrel is dark with a white rump patch. Research indicates that there are no genetic differences between the ashy storm-petrel populations on the Farallon and Channel Islands and there are no recognized subspecies.
The Service published a not warranted finding for this species in 2009, which was challenged by the Center for Biological Diversity. Today’s announcement complies with the terms of a 2011 settlement agreement whereby the Service is required to submit to the Federal Register by Sept. 30, 2013 a proposed listing rule or a not warranted finding.

A copy of the 12-month finding and other information about ashy storm-petrel is available at or by contacting Steve Martarano, at the Bay-Delta Fish and Wildlife Office at (916) 930-5643. Photos of the ashy storm-petrel and a distribution map can be located and downloaded from the Bay-Delta FWO image library at

The Service encourages the public to continue to submit any new information concerning the status of, and threats to, the ashy storm-petrel which will help the Service monitor and support the ongoing management of this species. Information should be sent to the Bay-Delta Fish and Wildlife Office, 650 Capitol Mall, Eighth floor, Sacramento, CA, 95814.

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