Center for Biological Diversity

For Immediate Release, January 11, 2023


Quinn Read, (206) 979-3074,

Oregon Butterfly Is Endangered Species Act Success

Fender’s Blue Butterfly Moved From Endangered to Threatened Status

PORTLAND, Ore.— The U.S. Fish and Wildlife Service announced today that the Fender’s blue butterfly will be downlisted from endangered to threatened under the federal Endangered Species Act. This action is based on the recovery of butterfly populations in Oregon’s Willamette Valley.

“The Endangered Species Act has ensured the full recovery of more than 50 species, and the Fender’s blue is now well on its way,” said Quinn Read, Oregon policy director at the Center for Biological Diversity. “This little butterfly was nearly lost to Oregon, but now we can celebrate its recovery along with the 50th anniversary of the landmark law that saved this species.”

The Fender’s blue is a tiny butterfly with a 1-inch wingspan. It’s found only in the prairie and oak savannah of the Willamette Valley. The species is so rare that it was presumed extinct until small populations were rediscovered in 1989.

When the Service listed the Fender’s blue as endangered in 2000, fewer than 4,000 of the butterflies were known to live in the wild. Although Fender’s blue numbers have fluctuated over the years, a 2016 survey found populations had grown to 29,000 total individuals.

Fender’s blue butterflies are completely dependent upon threatened Kincaid's lupine, a flowering plant that is the butterflies’ primary host. The butterfly remains highly vulnerable to climate change, as rising temperatures harm the lupine and other plants it needs to survive.

The Service cited management efforts to restore and maintain prairie habitat in the Willamette Valley as benefiting the species. The Fender’s blue will continue to be protected as a threatened species, and the Service has developed a rule to ensure its continued recovery in the years to come.

“This year marks the 50th anniversary of the Endangered Species Act, and the hopeful story of the Fender’s blue butterfly demonstrates once again that this is the most effective tool we have to stop extinction,” Read said.

Fender's blue butterfly. Photo by Oregon Department of Transportation. Image is available for media use.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

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