Inmates at Oregon's Coffee Creek Correctional facility released nearly 750 endangered butterflies into the wild this week, for the second time ever in Oregon.

The butterflies, Taylor's checkerspots, used to be abundant in Pacific Northwest prairies. But habitat degradation, due to urban development and agriculture, has stripped the species of 99 percent of its grassland ecosystem.

Since 2017, Coffee Creek's inmates have helped run a butterfly conservation lab, in which they care for adult, egg-laying checkerspots and then raise caterpillars to be transferred to native habitats.

This week and last week, Coffee Creek inmates transferred 750 checkerspots to conservation biologists at the U.S Fish and Wildlife Service to be released to prairies near Corvallis. Last year, inmates in the program released 562 of the butterflies. The releases are the only two to ever occur in Oregon, where statewide only two known checkerspot populations remain.

Butterfly keeper Julia Low (foreground) holds a jar of tiny buttefly larva during a tour of Coffee Creek inamtes and correction officials at the Oregon Zoo’s Butterfly Lab. © Oregon Zoo / photo by Michael Durham.
Butterfly keeper Julia Low (foreground) holds a jar of tiny buttefly larva during a tour of Coffee Creek inamtes and correction officials at the Oregon Zoo’s Butterfly Lab. © Oregon Zoo / photo by Michael Durham.

The Oregon Zoo has been working to restore checkerspot populations throughout the Pacific Northwest since 2004. Last month, it transferred a record 5,398 caterpillars to the Washington Department of Fish and Wildlife to be released in the Puget Sound area.

The Coffee Creek butterfly lab is a partnership with the Oregon Zoo, the USFWS and the Institute for Applied Ecology and is funded by the USFWS and a Oregon Zoo Foundation grant. In the program, zoo staff help train inmates to both care for the butterflies and the plants that feed them.

"Bringing butterfly conservation work into a medium-security housing unit continues to be a rewarding process," Oregon Zoo butterfly conservationist Ronda Naseth, who advises the program at Coffee Creek, says in a statement. "The butterfly team is thrilled to have partners who are working so diligently at providing the lab with beautiful harvests, and we are exceptionally proud of the quality of larvae being released this year. "