Island marble butterfly

The island marble butterfly is found only on the southern tip of San Juan Island in Washington. The state Department of Fish and Wildlife proposes to enroll landowners, including farmers and ranchers, into a voluntary conservation program.

Washington Fish and Wildlife proposes that farmers and ranchers on San Juan and Lopez islands voluntarily plant forage for a rare butterfly as a hedge against running afoul of the Endangered Species Act.

The department's federal counterpart, the U.S. Fish and Wildlife Service, may list the island marble butterfly as an endangered species. If so, landowners who already have created habit would be shielded from prosecution for inadvertently killing, injuring or harassing a protected butterfly.

The vegetation patches, at least 50 square feet per acre, couldn't be mowed, grazed or sprayed. The plan, with its restrictions, has not caused much alarm among producers, many of whom support providing habitat, said Brook Brouwer, Washington State University Extension's director for San Juan County.

"Personally, I didn't hear too much pushback from the agricultural community," he said. "I think for producers, they don't see this as a major concern at this point."

Fish and Wildlife has submitted the conservation plan to the USFWS for approval. The department has used the same approach to recovering species such as the sage grouse and fishers, a type of weasel.

The USFWS proposed listing the island marbled butterfly last year, but has not made a final decision. On May 21, it put the state's conservation plan online for public comment at

No one reported seeing an island marbled butterfly for 90 years. When one was documented in 1998 on San Juan Island, biologists searched from north Puget Sound to the Canadian border for more. The butterfly was found on only San Juan and Lopez islands.

Today, they are known only on the southern tip of San Juan Island in a national historic park. A survey in 2008 counted 63. Since then, more habit has been lost, particularly to agriculture and new homes, according to a Fish and Wildlife report. "We do know it's declining rapidly," said Ruth Milner, Fish and Wildlife district biologist. 

A homeowners association and San Juan County government have committed to enrolling in a conservation program. About a dozen other landowners have indicated an interest, Milner said.

"There's a lot of interest and pride in protecting it," she said. "It's such a unique situation. This butterfly exists in only one place. ... It's not a grizzly bear."

Fish and Wildlife has designated more than 8,000 acres in the valleys of the two islands as the best lands for habitat. Farms and rural homes are in the valleys, according to Fish and Wildlife. The butterfly doesn't inhabit forests.

Deer eat butterfly forage. Landowners can reduce the space they must devote to habitat by one-third if they fence the patches or let deer on their property be shot or hunted.

Milner said climate change also threatens the butterfly because hotter springs throw the life cycles of the butterflies and forage out of sync.

The main agricultural activities on the islands include growing hay and grazing livestock, Brouwer said.

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