Rana boylii pop. 2

Foothill yellow- legged frog - Feather River DPS

Family: Ranidae · Class: Amphibia · Order: Anura

Conservation status: ST · Threatened · G3T2 S2

The Foothill yellow-legged frog is a small to medium-sized amphibian with rough, pebbly skin that is generally mottled gray, olive, or brown. The species derives its common name from the distinctive yellow coloration on its belly and the underside of its hind legs. Adults typically measure 32 to 70 mm (1.3 to 2.8 inches) in snout-vent length, with females generally larger than males. The Feather River Distinct Population Segment (DPS) of the Foothill yellow-legged frog occurs in the Sierra Nevada foothills and mountains of northern California. This population historically ranged throughout the Feather River watershed and adjacent drainages in the northern Sierra Nevada, including portions of Butte, Yuba, Nevada, Placer, and Sierra counties. Current distribution is significantly reduced from historical levels, with many local populations extirpated. This species inhabits foothill and mountain streams with rocky substrates, typically at elevations ranging from near sea level to approximately 1,830 meters (6,000 feet). Foothill yellow-legged frogs require perennial or near-perennial streams with areas of shallow, flowing water interspersed with deeper pools. They prefer streams with cobble, boulder, or bedrock substrates that provide refugia and egg-laying sites. Riparian vegetation provides important terrestrial habitat for juveniles and adults. The species occurs in various vegetation types including valley-foothill hardwood, valley-foothill hardwood-conifer, and riparian forests. Foothill yellow-legged frogs are semi-aquatic, spending time both in streams and adjacent terrestrial habitats. Adults are primarily active during daylight hours and feed on a variety of invertebrates including flies, beetles, ants, and spiders. Breeding occurs from March through May, depending on water temperature and flow conditions. Females deposit egg masses containing 200 to 1,000 eggs attached to the undersides of rocks in shallow, flowing water. Tadpoles require three to four months to metamorphose, typically transforming from July through September. The species exhibits strong site fidelity, with adults often returning to the same stream reaches for breeding. The U.S. Fish and Wildlife Service listed the Feather River DPS as threatened under the Endangered Species Act in December 2021 (86 FR 73914). California also lists this population as threatened under the California Endangered Species Act. According to the Species Status Assessment, historical declines resulted from mining activities and altered hydrology related to California's water infrastructure development (USFWS 2021). Current threats include water diversions and dam operations that alter natural flow regimes, competition and predation by non-native species such as bullfrogs and fish, habitat degradation, and climate change effects on stream flows. The U.S. Fish and Wildlife Service proposed 192,275 acres of critical habitat for this population in January 2025 to support recovery efforts.

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, and more.