Pacific Southwest Region
California, Nevada and Klamath Basin

Twelve-Month Status Review of Four Great Basin Butterflies Finds Listing Not Warranted

Aug 31, 2012

Contact: Jeannie Stafford, (775) 861-6300

Twelve-Month Status Review of Four Great Basin Butterflies Finds Listing Not Warranted

The U.S. Fish and Wildlife Service (Service), today, announced that listing the Baking Powder Flat blue butterfly (Euphilotes bernardino minuta), bleached sandhill skipper (Polites sabuleti sinemaculata), Steptoe Valley crescentspot (Phyciodes cocyta arenacolor), and White River Valley skipper (Hesperia uncas grandiose) as either threatened or endangered under the Endangered Species Act (ESA)  is not warranted after completing a thorough review of all available scientific and commercial information.  

The four butterfly subspecies are native to the Great Basin in Nevada.  The Baking Powder Flat blue butterfly occurs in Lincoln and White Pine Counties; the bleached sandhill skipper occurs in Humboldt County; the Steptoe Valley crescentspot occurs in White Pine County; and the White River Valley skipper occurs in Lincoln, Nye, and White Pine Counties. 

In making the determination, the Service analyzed potential factors that may affect the habitat or range of the butterflies including water development, fire, livestock grazing, nonnative plant invasion, agriculture, recreation (off-highway vehicles), mining and energy development, climate change, overutilization due to collecting, disease and predation, limited distribution and small population size, and inadequate existing regulatory mechanisms.  

“Our analysis found none of these potential threats alone or in combination threaten the four subspecies across all or in any significant portion of their ranges,” said Ted Koch, State Supervisor for the Nevada Fish and Wildlife Office. 

This status review was prepared in response to a petition received January 29, 2010, from WildEarth Guardians requesting that 10 subspecies of Great Basin butterflies in Nevada and California be listed as threatened or endangered with critical habitat under the ESA.  On October 4, 2011, the Service published a 90-day finding indicating the petition did not present substantial scientific or commercial information that listing six of the 10 subspecies (Carson Valley silverspot, Carson Valley wood nymph, Mattoni’s blue butterfly, Mono Basin skipper, and the two Railroad Valley skipper subspecies) was warranted and that substantial information was presented for the remaining four butterflies included in this 12-month status review. 

The Service requests that any new information on the status of or threats to these butterflies be sent to Ted Koch, Nevada Fish and Wildlife Office, 1340 Financial Blvd., Suite 234, Reno, Nevada 89502, as it becomes available.  New information will help the Service monitor the subspecies and encourage its conservation.  For further information about the Great Basin butterflies and this finding, please visit the Service’s Nevada Fish and Wildlife Office web site at


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