Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for the Carson Wandering Skipper

We, the U.S. Fish and Wildlife Service (Service), determine the Carson wandering skipper (Pseudocopaeodes eunus obscurus) to be endangered under the Endangered Species Act of 1973, as amended (Act). The Carson wandering skipper is currently known from only two populations, one in Washoe County, Nevada, and one in Lassen County, California. The subspecies is found in grassland habitats on alkaline substrates. Extinction could occur from naturally occurring events or other threats due to the small, isolated nature of the known populations of the Carson wandering skipper. These threats include habitat destruction, degradation, and fragmentation due to urban and residential development, wetland habitat modification, agricultural practices (such as excessive livestock grazing), gas and geothermal development, and nonnative plant invasion. Other threats include collecting, livestock trampling, water exportation projects, road construction, recreation, pesticide drift, and inadequate regulatory mechanisms. We find these threats constitute immediate and significant threats to the Carson wandering skipper. This rule implements Federal protection provided by the Act for the subspecies.