ETWP; Proposed Endangered Status for the Southern California Distinct Vertebrate Population Segment of the Mountain Yellow-Legged Frog

We, the Fish and Wildlife Service (Service), propose to list the southern California distinct vertebrate population segment (DPS) of mountain yellow-legged frog (Rana muscosa) as endangered, pursuant to the Endangered Species Act of 1973, as amended (Act). In southern California, this DPS has been reduced to only a few isolated remnants in the San Gabriel, San Jacinto, and San Bernardino Mountains. Hypothesized causes of the decline include predation from introduced trout or possibly some other widespread environmental effects such as airborne contaminants. These effects have probably acted in combination to produce the decline. The chronology of the decline is not well documented, but it appears that a precipitous decline occurred over the last three or four decades. The decline went largely unnoticed and was not studied. In addition to predation from trout and other widespread factors, the few remaining frogs are now threatened by recreational suction dredging for gold and human activities at campgrounds and day use areas. The remnant populations are so small that they are now at risk from random genetic, demographic, and environmental effects as well. This proposed rule constitutes the 12-month finding on a petition to list the southern California population of mountain yellow-legged frog as threatened or endangered. This proposed rule, if made final, would implement the Federal protection and recovery provisions afforded by the Act for this DPS. We welcome data and comment from the public on this proposal.