Sierra Nevada yellow-legged frog Monitoring Project

Plumas Audubon Society is currently monitoring the last extant genetic lineage of Diamond Mountain Sierra Nevada yellow-legged frogs (Rana sierrae). Although trends are not great within the current population, there is hope for restoration through Plumas National Forest’s partnership with the San Francisco Zoo.

The 2007 Moonlight Fire burned through much of the upper Indian Creek watershed, and was of particularly high severity in the Lone Rock Valley area, where a declining population of the federal- and state-listed endangered Sierra Nevada yellow-legged frog exists. In 2021, the Dixie Fire burned through the Lone Rock Creek watershed again. In 2023, the population was estimated to be at below 50 individuals.

As part of our long-running partnership with the Plumas National Forest, amphibian surveys were performed by PAS in all sub-basins, where, in 2022, no sightings had been made within ten years. In 2023, 48 tadpoles were found and transported to the San Francisco Zoo for captive rearing and reintroduction. 47 out of 48 of these tadpoles survived to adulthood and were reintroduced to the watershed in Spring 2024!

The goal of this project is to continue monitoring the population via extensive snorkeling and visual encounter surveys, and locate any egg masses and/or tadpoles for immediate translocation to the San Francisco Zoo rearing facility. The purpose of this project is to preserve the genetic integrity of the Diamond Mountain Sierra Nevada yellow-legged frog population by rearing the eggs/tadpoles in the zoo environment, which is free from introduced and historically stocked predatory fish populations.

PAS staff are trained and permitted to handle these endangered amphibian species. Surveys for these species should not be conducted without supervision from a qualified biologist.