SANTA FE, NEW MEXICO—Today, the U.S. Fish and Wildlife Service released a proposed rule to list a rare subspecies of silverspot butterfly (Speyeria nokomis nokomis) as “threatened” under the Endangered Species Act (ESA). WildEarth Guardians petitioned to list the butterfly in 2013 due to threats from habitat loss, insecticides, and climate change.
Silverspots live in scattered populations in the desert Southwest and rely on the bog violet (Viola nephrophylla), a flower that provides the exclusive food source for silverspot larvae. The habitats for both the butterfly and the flower—seeps, springs, wet meadows, and other riparian oases—have been decimated by water diversions, housing developments, mining, livestock grazing, drought, and climate change.
“Listing offers silverspots a much-needed lifeline,” said Joe Bushyhead, endangered species attorney with WildEarth Guardians. “We’re hopeful the ESA can provide a path to both recover the butterfly and safeguard its vanishing habitat.”
Recent research has shown the range of silverspots to be more limited than previously thought. Genetic analysis now indicates that the butterfly, previously known as the Great Basin silverspot, lives only in east-central Utah, western and south-central Colorado, and north-central New Mexico–well east of the Great Basin region.
The Fish and Wildlife Service is accepting comments on its proposed rule from tomorrow until July 5, after which the agency will finalize its listing decision.