U.S. Fish & Wildlife Service

Sacramento Fish & Wildlife OfficeServing the people, conserving the fish, wildlife, and plants of California

A Unit Of The Pacific Southwest Region

News Release

Four Great Basin Butterflies May Warrant Protection Under the Endangered Species Act

October 3, 2011

Contact: Jeannie Stafford, U.S. Fish & Wildlife Service
o:(775) 861-6300

The U.S. Fish and Wildlife Service (Service) today announced that four butterfly subspecies native to the Great Basin of Nevada may warrant federal protection as a threatened or endangered species under the Endangered Species Act (ESA).

Today’s decision, commonly known as a 90-day finding, is based on scientific information about the subspecies provided in a petition requesting protection of the subspecies under the Endangered Species Act (ESA) and in the Service’s files. The Service will now undertake a more thorough status review of the butterflies – 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 grandiosa) – to determine whether to propose adding the subspecies to the Federal List of Endangered and Threatened Wildlife.

“The finding does not mean that the Service has decided it is appropriate to list the four butterfly subspecies,” said Jill Ralston, acting state supervisor for the Nevada Fish and Wildlife Office. “We are encouraging the public to submit any relevant information about the four butterflies and their habitat to us for consideration in the comprehensive review.” 
The Baking Powder Flat blue butterfly occurs in Lincoln and White Pine Counties in Nevada; the bleached sandhill skipper occurs in Humboldt County, Nevada; the Steptoe Valley crescentspot occurs in White Pine County, Nevada; and the White River Valley skipper occurs in Lincoln, Nye, and White Pine Counties in Nevada.
The petition asserts that primary threats to these butterflies include:  impacts from water development, agriculture, livestock grazing, pesticide use, climate change, inadequate existing regulatory mechanisms, as well as the small populations and limited distribution of these subspecies.
The Service’s finding was made following review of a petition seeking to protect ten butterflies occurring in the Great Basin. The Service found that the petition did not present substantial scientific or commercial information indicating that listing the remaining six Great Basin butterflies included in the petition may be warranted.

The Service determined no further action will be taken on the following six butterflies: Mattoni’s blue butterfly (Euphilotes pallescens mattonii), Mono Basin skipper (Hesperia uncas giulianii), Carson Valley silverspot (Speyeria nokomis carsonensis), Carson Valley wood nymph (Cercyonis pegala carsonensis), and Railroad Valley skippers, (Hesperia uncas fulvapalla) and (Hesperia uncas reeseorum).
To ensure this status review is comprehensive, the Service is soliciting information from state and federal natural resource agencies and all interested parties regarding the four Great Basin butterflies and their habitat. Based on the status review, the Service will make one of three possible determinations for each subspecies:

  • Listing is not warranted, in which case no further action will be taken.
  • Listing as threatened or endangered is warranted. In this case, the Service will publish a proposal to list, solicit independent scientific peer review of the proposal, seek input from the public, and consider the input before a final decision about listing the subspecies is made. In general, there is a one-year period between the time a species is proposed and the final decision.
  • Listing is warranted but precluded by other, higher priority activities. This means the subspecies is added to the federal list of candidate species, and the proposal to list is deferred while the Service works on listing proposals for other species that are at greater risk. A warranted but precluded finding requires subsequent annual reviews of the finding until such time as either a listing proposal is published, or a not warranted finding is made based on new information.

The finding will publish in the Federal Register on October 4, 2011. Written comments regarding the four Great Basin butterflies proposal may be submitted by one of the following methods:

  • Federal eRulemaking Portal: http://www.regulations.gov.Follow the instructions for submitting comments to Docket No. [FWS–R8–ES–2010–0097].
  • U.S. mail or hand-delivery: Public Comments Processing, Attn: Docket No. [FWS–R8–ES–2010–0097]; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 2042-PDM; Arlington, VA 22203.


Comments must be received within 60 days, on or before December 5, 2011. The Service will post all comments on http://www.regulations.gov. This generally means the agency will post any personal information provided through the process. The Service is not able to accept email or faxes.

For further information about the Great Basin butterflies and this finding, please visit the Service’s Nevada Fish and Wildlife Office web site at http://www.fws.gov/nevada/.

The ESA provides a critical safety net for America’s native fish, wildlife and plants. The Service working to actively engage conservation partners and the public in the search for improved and innovative ways to conserve and recover imperiled species. To learn more about the Endangered Species Program, visit http://www.fws.gov/endangered/.

Last updated: December 4, 2017