Сиера-Невада сары аяқты бақасы

Species of amphibian

Speciesbox
| status = EN
| status system = IUCN3.1
| status ref =
| image = Rana muscosa. jpg
| taxon = Rana muscosa
| authority = Camp, 1917
| synonyms =
| synonyms ref = separated into two distinct population segments (DPS): a northern DPS, listed endangered in 2014, and a southern DPS that was listed endangered in 2002. Populations formerly classified as Rana muscosa in the northern Sierra Nevada have since been redescribed as a new species: Rana sierrae, the Sierra Nevada yellow legged frog. The Sierra Nevada yellow legged frog has also been classified as a federally endangered species since 2014. Its color and patterning are variable. It is yellowish, brownish, or olive with black and brown markings. The underside of its hind legs can be different hues of yellow, from a bold sun yellow to a lighter pale yellow; larger ones may can hints of orange on their hind legs. The throats of it range from white to yellow. Along with its variable coloration, the frog also has a dorsal pattern with dark spots in different shapes and sizes. Its species name muscosa is from the Latin meaning "mossy" or "full of moss", inspired by its coloration. It may have light orange or yellow thighs. When handled, the frog emits a defensive odor reminiscent of garlic.

The frog occurs in mountain creeks, lakes and lakeshores, streams, and pools, preferring sunny areas. It rarely strays far from water, and can remain underwater for a very long time, likely through cutaneous gas exchange. As such, adults can be found on rocks around shorelines. Close proximity to water is important because eggs are either laid underwater attached to rocks or in shallow waters. The tadpoles require a permanent water habitat for at least two years while they develop. This is because tadpoles can die from a lack of moisture, especially dry summers. The frog has been noted at elevations of between about in Southern California. The frog was known from 166 locations in the Southern California mountains, and as of 2007, only seven or eight remained. The frog is represented in the Sierra Nevada by three or four populations. chytrid fungus, and probably pesticides, drought, and ultraviolet radiation.

Trout were introduced to lakes and streams throughout the Sierra Nevada in the late 1800s to increase recreational fishing in the area. 90% of these Sierra Nevada lakes and streams did not previously have fish in them, although the trout were regionally present. The fish feed on tadpoles, a main prey item. Some of the fish types that prey on tadpoles include the brown, golden, and rainbow trout, as well as the brook char.

The decline of the frog from its historic range has been associated with pesticide drift from agricultural areas. Frogs that have been reintroduced to water bodies cleared of fish have failed to survive, and analysis has isolated pesticides in their tissues. The relative roles that pesticides and introduced fish play in frog declines are still debated, and the loss of R. muscosa in its former range has probably been influenced by multiple factors.

This species is one of many amphibians affected by the fungal disease chytridiomycosis. Ample research has explored the biology of the fungus and how to prevent related amphibian declines. Infection in a tadpole can be identified by changes in the pigmentation of these parts. Adults have keratin rich skin and suffer worse infections. In studies, healthy adult frogs exposed to infected frogs for at least two weeks developed the disease. Transmission takes longer in tadpoles, generally over seven weeks. Studies indicate that R. muscosa is naturally more susceptible to the chytrid fungus than many other frogs.

The frog is an endangered species under the US Endangered Species Act. The first successful captive breeding of the frog occurred in 2009 when three tadpoles were reared at the San Diego Zoo. Conservation workers at the zoo plan to release any more surviving captive bred frogs in the San Jacinto Mountains, part of their native range. In 2015 frogs and tadpoles of the species were reintroduced to Fuller Mill Creek in the San Bernardino Mountains and San Bernardino National Forest. They were bred and raised the Arnold and Mabel Beckman Center for Conservation Research in Escondido, one of the organizations that have partnered with the San Diego Zoo Institute for Conservation Research (ICR) to save the species from extinction. In 2015, the Oakland Zoo began a rehabilitation project of the frog in order to fuel efforts to save the species. Every year, a group of tadpoles are taken from native lakes throughout California and brought to the zoo. There, the tadpoles are grown to juvenile frogs, while also undergoing an inoculation process to render them immune to the chytridiomycosis fungus disease. Once ready, the now chytrid immune juvenile frogs are released back into the lakes they were found. In 2016, the Oakland Zoo released 53 specimens into various lakes in Sequoia and Kings Canyon National Parks. The program is set to release 130 inoculated individuals into lakes in Sequoia and Kings Canyon National Parks and Inyo National Forest in 2017. In 2021, the Aquarium of the Pacific partnered with government organizations like the California Department of Fish and Wildlife to create a facility for taking care of mountain yellow legged frogs. This was in response to recent wildfires which harmed their habitats. Following the wildfires, wildlife agencies found and moved these frogs into places like the facility established by the Aquarium of the Pacific. These efforts help the species recover from natural disasters and prevent extinction.