Pacific Southwest Region
California, Nevada and Klamath Basin

Service Proposes to Protect the Mt. Charleston blue butterfly and Five Similar Butterflies Under the Endangered Species Act

Sep 26, 2012

September 26, 2012
Contact: Dan Balduini, 702-515-5480


Service proposes to protect the Mt. Charleston blue butterfly and five similar butterflies under the Endangered Species Act
Agency seeks information from the public, scientific community before making final decision

LAS VEGAS-Current evidence suggests that the Mt. Charleston blue butterfly is in danger of becoming extinct in the foreseeable future, the U.S. Fish and Wildlife Service announced today. As a result, the Service proposes to protect the species under the Endangered Species Act, and is seeking new information from the public and the scientific community that will assist the agency in making a final determination.

Additionally, the Service proposes listing as threatened five butterflies that are similar in appearance to the Mt. Charleston blue and occur in the blue’s habitat.

The Mt. Charleston blue is a species of butterfly that occupies high elevations of the Spring Mountains in the Spring Mountains National Recreation Area, located approximately 25 miles west of Las Vegas. Currently, the Mt. Charleston blue butterfly is known to occupy only two of its 16 historical locations, while it is presumed the butterfly occupies eight of those historical sites.

The Service first identified the Mt. Charleston blue butterfly as a candidate for ESA protection in 2011, due to the threat posed by the loss and degradation of habitat and inadequate regulatory mechanisms to prohibit collection of the butterfly. The species will continue to experience habitat loss due to fire suppression and succession, implementation of recreation development projects and fuels reduction projects, increases in nonnative plants, and extreme precipitation events and drought, which are likely to become more frequent under climate change.

The five butterflies the Service is recommending for listing as threatened (based on similarity of appearance to and occurring within the habitat of the Mt. Charleston blue) are the Lupine blue butterfly (Plebejus lupini texanus), Reakirt’s blue butterfly (Echinargus isola), Spring Mountains icarioides blue butterfly (Plebejus icarioides austinorum), and two Spring Mountains dark blue butterflies (Euphilotes ancilla cryptica & Euphilotes ancilla purpura). The differences between all five butterflies are subtle and undetectable to the untrained eye. Only populations of the five butterflies that occur within the Mt. Charleston blue butterfly’s habitat are proposed for listing as threatened.

The final decision to add the Mt. Charleston blue butterfly and the five similar butterflies to the Federal List of Endangered and Threatened Wildlife and Plants will be based on the best scientific information available. The Service will open a 60-day public comment period on September 27, 2012, to allow the public to review and comment on the proposal and provide additional information. All relevant information received from the public, government agencies, the scientific community, industry, or any other interested parties will be considered and addressed in the agency’s final listing determination for the species. 

Today’s decision is part of the Service’s efforts to implement a court-approved work plan that resolves a series of lawsuits concerning the agency’s ESA Listing Program. The intent of the agreement is to significantly reduce litigation-driven workloads and allow the agency to focus its resources on the species most in need of the ESA’s protections over the next five years.

Comments and information may be submitted by the following methods: 

  • Federal eRulemaking Portal: Follow the instructions for submitting comments. 
  • U.S. mail or hand-delivery: Public Comments Processing, Attn: FWS-R8-ES-2012-0069; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, Suite 222; Arlington, VA 22203. 

Comments must be received or on or before November 26, 2012. 

More information is available online at (Docket Number FWS-R8-ES-2012-0069) and at

A photo of the Mt. Charleston blue butterfly is available on the Pacific Southwest Region's Flickr site

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