These efforts are part of the Sustainability in Prisons Project (SPP), the brainchild of Nalini Nadkarni of the University of Utah in Salt Lake City. “A lot of her work is about coming down from the ivory tower and involving under-served audiences in science,” says Dennis Aubrey, a student who works in the checkerspot initiative. He spoke about the project at the 2012 Ecological Society of America Annual Meeting in Portland, Oregon.

The SPP works with prisons throughout Washington, and treats the inmates as collaborators rather than labourers. They apply for the positions and get training, education and a small wage. Together, they have helped to conserve endangered butterflies, frogs, flowering plants and moss.

Prisons may seem to be an unorthodox location for conservation work, but Carri LeRoy, project co-director of the SPP, says: “There’s a lot of clean, controlled space, and people with time on their hands, looking to do something valuable and change their lives.”

“Most people are in the prison yard talking about who did them wrong,” says Aubrey. “Then, all of a sudden, guards will tell us they hear people saying, ‘Hey did you see how that moss was growing?’ ”

The women in the checkerspot project have already reintroduced more than 800 of the butterflies into the wild, and raised more than 3,600 caterpillars for next year’s release. The Taylor’s checkerspot is found in just four small populations in Washington and Oregon, and it now lays its eggs on plantain, an introduced species. No one knew what the butterfly’s original host plants were. The inmates found out by allowing the adults to choose between three candidates and showed that they prefer to lay eggs on two native species — the harsh paintbrush and golden paintbrush — rather than the exotic plantain.