Fender’s blue butterfly population rebounds in the Willamette Valley

BPA and the work of its many environmental partners has helped set the Fender’s blue butterfly species in Oregon on the road to recovery. The U.S. Fish and Wildlife Service will reclassify the butterfly from endangered to threatened in February 2023.

“This is a tremendous success story – to go from nearly extinct to on the road to recovery,” said Craig Rowland, deputy state supervisor for the service’s Oregon office. “We’ve only reached this point of being able to down-list because of successful partnerships with landowners, conservation agencies, businesses and other agencies.”

Found only in the Willamette Valley, scientists once believed Fender’s blue butterfly to be extinct in the 1930s. However, thanks to the U.S. Fish and Wildlife Service, BPA ratepayers, and many other on-going conservation efforts the insect’s population has quadrupled over the past 20 years. 

Through its land acquisition program, BPA has set aside land in the Willamette Valley that supports the butterfly and many other types of insects, fish and wildlife. The Smithfield Oaks property is just one example of the many projects BPA ratepayers have helped to acquire for wildlife habitat protection. Located in Polk County, the 183-acre property has a large and growing population of Fender's blue butterfly and its primary host plant, Kincaid's lupine, the main plant the butterfly reproduces on. BPA funded the acquisition of the property in 2019 through its Willamette Wildlife Mitigation Program and received a conservation easement with the Polk Soil and Water Conservation District to protect the property from development in perpetuity.

Scientists say habitat loss is the main threat to the butterfly which has an adult phase of only 7-14 days. Mating occurs within that short window of time.

Thanks to Willamette Valley conservation efforts, the butterfly’s population expanded from nearly 3,000 individuals in 2000 to almost 14,000 in 2018.