The Fish and Wildlife Service proposed Tuesday adding a rare Nevada butterfly called the bleached sandhill skipper to the federal list of endangered species. Citing potential threats that include climate change and groundwater pumping, the federal agency agreed with environmentalists in determining the butterfly warrants Endangered Species Act protections. “The bleached sandhill skipper is a desert occupant, likely living close to its upper thermal limits under normal conditions, leaving little buffer for accommodating warming and drying conditions,” FWS stated, adding that “the climate within [the] bleached sandhill skipper range has been drying and warming over the last several decades.”