After 18 Years, the Island Marble Butterfly Finally Receives Federal Protection

In response to a petition filed by the Xerces Society in 2012, the U.S. Fish and Wildlife Service (USFWS) finalized listing the island marble butterfly (Euchloe ausonides insulanus) as an endangered species under the Endangered Species Act (ESA) and designated critical habitat. The Xerces Society and other conservation groups first petitioned the USFWS to protect the island marble butterfly as an endangered species in 2002. In 2006, the USFWS denied protection to the butterfly citing voluntary conservation efforts. When monitoring by the Washington Department of Fish and Wildlife and others indicated that the butterfly’s populations were continuing to decline, the Xerces Society again petitioned the USFWS in 2012.

When the Xerces Society first petitioned for this butterfly’s protection, it was found at multiple sites, including populations on both Lopez and San Juan islands. Unfortunately, the island marble now only occurs in one population within American Camp National Park on San Juan Island, which makes recovery much more difficult. In 2019, the USFWS approved a Programmatic Candidate Conservation Agreement with Assurances (CCAA) for the island marble butterfly in San Juan County, Washington. The CCAA is a voluntary agreement with landowners to promote conservation that reduces threats and provides for voluntary action to help recovery. Many landowners have signed up for the CCAA, which could give this butterfly a chance at survival.

“We hope that now the island marble is listed, funding can be made available to help the butterfly recover,” said Scott Black. “If we can act quickly, our grandchildren might still be able to experience this wonderful animal.