skip to content
The endangered Miami blue butterfly feeds on a flower. © Holly Salvato. Used with permission.

Fish and Wildlife Service emergency lists Miami blue butterfly as endangered

Vero Beach, Florida – The U.S. Fish and Wildlife Service (Service) announced today that it is taking emergency action to protect the Miami blue butterfly. Upon publication of the emergency rule on Aug. 10, 2011 in the Federal Register, the Miami blue becomes listed as endangered under the Endangered Species Act (ESA). The emergency listing immediately protects the butterfly for 240 days. Concurrently, the Service is issuing a proposed rule to permanently put into place the protections for the Miami blue beyond the 240-day emergency period.

The Miami blue is a small, coastal, non-migratory butterfly endemic to south Florida. Its geographic range once extended from the Dry Tortugas north along the Florida coasts to about St. Petersburg and Daytona, but it is now restricted to a few, small, remote islands within the Florida Keys. In making this emergency listing determination, the Service has carefully assessed the best scientific and commercial information available regarding the past, present, and future threats faced by the Miami blue butterfly.

Under the emergency provisions of the ESA, the Service is also listing the cassius blue butterfly, ceraunus blue butterfly, and nickerbean blue butterfly as threatened throughout their natural ranges due to their similarity of appearance to the Miami blue. These three butterflies overlap in range with the Miami blue in south Florida, but their entire natural ranges include the Cayman Islands, Bahamas, Cuba and Greater Antilles. In addition, the Service is issuing a 4(d) special rule on these species to establish prohibitions on collection and commercial trade within the United States. This action also prohibits the import into, and export from, the United States of the three similar butterflies. Otherwise lawful activities that may impact these similar butterflies—such as legal use of pesticides, mowing, and vehicle use—are not prohibited. Extending the prohibitions of collection, possession, and trade to the three similar butterflies will provide greater protection to the Miami blue.

The Miami blue butterfly is endangered due to the combined influences of habitat destruction and modification, herbivory of host plants by exotic green iguanas, accidental harm from humans, loss of genetic diversity, and catastrophic environmental events, such as hurricanes. Because of its small population size and restricted range, collection can severely impact the Miami blue.

Imminent threats now pose significant risk to the survival of the Miami blue. The Service believes emergency listing is necessary and, in this case, the normal listing timeframe is insufficient to prevent losses that may result in extinction. In addition, the Service has determined that designation of critical habitat for the Miami blue butterfly is not prudent because publishing maps and descriptions of critical habitat areas would widely announce the exact location of the butterfly to poachers, collectors, and vandals and may further facilitate disturbance and destruction of the butterfly’s habitat.

The Service is inviting public comment on the proposed rule to permanently list the Miami blue. The Service is seeking all available scientific or commercial information concerning existing threats, including collection and trade of the Miami blue butterfly. Other information, such as locations of any additional populations or habitat, as well as biological data, is also being sought. The finding will publish in the _Federal Register_ on August 10, 2011.

Written comments and information concerning the proposed rule can be submitted by one of the following methods:

  • Federal eRulemaking Portal: Follow the instructions for submitting comments to Docket No. [FWS–R4–ES–2011–0043].
  • U.S. mail or hand-delivery: Public Comments Processing, Attn: Docket No. [FWS–R4–ES–2011–0043]; 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 October 11, 2011. The Service will post all comments on This generally means the agency will post any personal information provided through the process. The Service is not able to accept email or faxes. Following the public comment period, the Service will decide if the proposed rule should be approved, revised, or withdrawn.

An animal or plant is designated as endangered if it is in danger of extinction throughout all or a significant portion of its range. Under section 4(b)(7) of the ESA, the Service may emergency list a species if the threats to that species constitute an emergency posing a significant risk to its well-being. Based on the immediate and ongoing significant threats to the Miami blue butterfly throughout its entire occupied range and the fact that the butterfly is restricted to only one confirmed population, the Service has determined that the Miami blue is in danger of extinction throughout all of its range. Emergency listing rules take effect immediately upon publication in the Federal Register, but expire after 240 days unless the species is listed following the normal listing procedures during that 240-day period. The proposed rule published concurrently on Aug. 10, 2011 in the _Federal Register_ will, if finalized, accomplish this.

In May 2005, the Service recognized the Miami blue as a federal candidate species for listing in its annual Candidate Notice of Review. The Service is working with the State and many other partners on initiatives for the Miami blue, such as conducting additional surveys to search for other potential populations, assessing the extent of occupancy and size of the remaining population, and looking at options for controlling and reducing other threats, such as invasive iguanas.

For more information about the Miami blue butterfly, the emergency listing and proposed rule, please visit or

The ESA provides a critical safety net for America’s native fish, wildlife, and plants. The Service is 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


Division of Public Affairs
External Affairs
Telephone: 703-358-2220

The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. For more information on our work and the people who can make it happen, visit Connect with the Service on Facebook, follow our tweets, watch the YouTube Channel and download photos from Flickr.

Contact Us:

Looking for a media contact? Reach out to a regional spokesperson.

Share this page

Tweet this page on Twitter or follow @USFWSsoutheast

Share this page on Facebook or follow USFWSsoutheast.


Share this page on LinkedIn