Alanna Madden

PORTLAND, Ore. (CN) — The U.S. Fish and Wildlife Service said Wednesday it will move the Fender’s blue butterfly from endangered to threatened under the federal Endangered Species Act after “improved” species recovery in its endemic Willamette Valley region.

“This is a tremendous success story — to go from nearly extinct to on the road to recovery,” said Craig Rowland, acting state supervisor for the service’s Oregon office, in a statement. “We’ve only reached this point of being able to downlist because of successful partnerships with landowners, conservation agencies, businesses, other agencies, and the work of our national wildlife refuges to conserve Fender’s butterfly. This is yet another species that is making incredible strides in Oregon.”

The Fender’s blue butterfly was first listed as endangered in 2000, although the species was thought to have gone extinct in 1937 before it was rediscovered in 1989. According to the Center for Biological Diversity, at the time of its listing fewer than 4,000 of the butterflies were known to live in the wild.

Today, the service says the butterflies now inhabit twice the acreage than in 2000, and its number of occupied sites has quadrupled. As such, the service has reclassified the Fender’s blue butterfly from endangered to threatened and has finalized a special rule that provides for the conservation of the species.

“We are finalizing a 4(d) rule that prohibits all intentional take of Fender’s blue butterfly and specifically allows incidental take by landowners or their agents while conducting management for the creation, restoration, or enhancement of short-stature native upland prairie or oak savannah conditions and a means to provide protective mechanism to our state and private partners so they may continue with certain activities that will facilitate the conservation and recovery of the species,” the service said in rule, which is effective 30 days after it's published in the Federal Register on Thursday.

“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, in a statement. “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.”