Biology of the Fender's blue butterfly (Icaricia icarioides fenderi Macy), an endangered species of western Oregon native prairies

The Fender's blue butterfly (Icaricia icarioides fenderi [Macy]) is an endangered butterfly found across 16 surviving remnants of native upland prairie in the Willamette Valley in Oregon, USA. A member of the lycaenid group, recent research suggests that the butterfly (a) is distinct from other subspecies in the L icarioides species complex, (b) requires sufficient quantities of its larval food plant, usually Kincaid's lupine (Lupinus sulphureus spp. kincaidii [Smith] Phillips), and adult nectar resources; (c) as a result of limited dispersal abilities and habitat fragmentation, has populations that are currently isolated from one another; (d) experiences high variation in population growth rate; and (e) has no populations that are at low risk of extinction. Recovery of this endangered species will require maintaining and restoring enough habitat to support viable populations of the butterfly throughout its range. These efforts should include stopping habitat loss, managing existing habitat by reducing aggressive weeds, enhancing nectar and food plant resources, restoring networks of habitat to support viable populations, and possibly developing a captive breeding program.