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The mountain yellow-legged frog (Rana muscosa), also known as the southern mountain yellow-legged frog, is a species of true frog endemic to California in the United States.[1][2] It occurs in the San Jacinto Mountains, San Bernardino Mountains, and San Gabriel Mountains in Southern California and the Southern Sierra Nevada. It is a federally listed endangered species,[3] separated into two distinct population segments (DPS): a northern DPS, listed endangered in 2014,[4] and a southern DPS that was listed endangered in 2002.[5]
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.[4] The mountains separating the headwaters of the South Fork and Middle Fork of the Kings River mark the boundary between the ranges of the two species.[1]
Rana muscosa is 4 to 8.9 centimetres (1.6 to 3.5 in) long. Females tend to be larger than males.[6] 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.[7] 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.[8]
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 1,214 and 7,546 feet (370 and 2,300 m) in Southern California.[1] These habitats are primarily found in north of California in Sierra Nevada and south of California in the Transverse ranges.
The frog emerges from its wintering site soon after snowmelt. Its breeding season begins once the highest meltwater flow is over, around March through May in the southern part of its range, and up to July in higher mountains to the north. Fertilization is external, and the egg cluster is secured to vegetation in a current, or in still waters sometimes left floating free. How long it takes for breeding onset varies from 1–4 years depending on the levels of snow and temperature. Very cold temperatures may cause death of larvae.[7] The juvenile may be a tadpole for 3 to 4 years before undergoing metamorphosis.[8] However, this rate heavily varies depending on the temperature and elevation of the area.[7] There are two classes of tadpoles: first year tadpoles and second year tadpoles. Metamorphosis tends to happen the second summer of tadpole life. They are called metamorphs when this transition from tadpole to young frog is occurring. They are then called a juvenile when it survives one winter. It becomes ready to reproduce after 2 years of the juvenile stage. It is found that the growth and development rate is slower at higher elevations.[7]
The frog lacks a vocal sac. Its call is raspy, rising at the end. During the day, it calls underwater.[8] The frogs tend to be less active during the winters and more active during the mating season. For years when there is heavy snow at high elevations, they may only be active for 90 days in the summer.[7] Hibernation tends to happen underwater or in the crevices of stream banks. This occurs during the cold months of winter. Hibernation ends in the spring to start the breeding season.[3] This species feeds on aquatic insects and benthic invertebrates. Their diet varies depending on the habitat type. When living in streams, it tends to eat terrestrial insects such as beetles, ants, bees, wasps, flies, and dragonflies.[7] They are also known to eat larvae of other frogs and toads, as well as commit cannibalism.[8]
Once a common species, Rana muscosa was absent from much of its native range by the 1970s. Over the course of the last hundred years, 90% of its populations have been eliminated.[9] The frog was known from 166 locations in the Southern California mountains, and as of 2007, only seven or eight remained.[1] The 2009 discovery of R. muscosa at two locations in the San Bernardino National Forest was newsworthy.[10] The frog is represented in the Sierra Nevada by three or four populations.[1] Its decline is attributed to many factors, including introduced species of fish such as trout, livestock grazing,[11] chytrid fungus,[12] and probably pesticides, drought, and ultraviolet radiation.[11] Recreational activities in streams have also had an impact.[13]
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.[14] 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.[15] The introduced trout have changed the distribution of several native species in the local ecosystems.[9] Most of the mountain yellow-legged frog populations did not evolve to adapt to the trout. The trout caused populations to isolate, restricted the amount of available habitats, and increased the chances of extinction. After the removal of fish from several lakes, the frog reappeared and its populations increased.[9] These frogs then began to disperse to other suitable habitats nearby.[16]
The decline of the frog from its historic range has been associated with pesticide drift from agricultural areas.[17][18] Frogs that have been reintroduced to water bodies cleared of fish have failed to survive, and analysis has isolated pesticides in their tissues.[19] Pesticides are considered by some authorities to be a greater threat to the frog than the trout.[20] 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.[19]
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.[12] The fungus attacks keratinized areas of a frog's body. Tadpoles are not severely affected because only their jaw sheaths and tooth rows are heavily keratinized.[21] Infection in a tadpole can be identified by changes in the pigmentation of these parts.[22] 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.[22] Frogs may be predisposed to infection if their immune systems are weakened by other factors, such as pesticide.[23] Studies indicate that R. muscosa is naturally more susceptible to the chytrid fungus than many other frogs.[24]
The frog is an endangered species under the US Endangered Species Act.[3] It is separated into two distinct population segments (DPS): a northern DPS, listed endangered since 2014,[4] and a southern DPS that was listed endangered in 2002.[5] The two DPS are separated by the Tehachapi Mountains, and occupy unique habitats: the northern DPS lives in lakes or slow-moving water bodies at alpine and subalpine elevations in the Sierra Nevada, while the southern DPS lives in faster flowing and warmer waters of the chaparral, although it may also occur at higher elevations in the Transverse Range.[4]: 24263–2464 In addition, the DPS show genetic divergence, likely reflecting ancient reproductive isolation.[4]: 24263–2464
The International Union for Conservation of Nature has also listed the mountain yellow-legged frog as endangered.[1] Its NatureServe conservation status is "critically imperiled."[25]
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.[15][26]
In 2015 frogs and tadpoles of the species were reintroduced to Fuller Mill Creek in the San Bernardino Mountains and San Bernardino National Forest.[27] 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.[27] The Los Angeles Zoo is also a coalition partner and is raising two groups of wild collected tadpoles from two localities in the San Gabriel Mountains where they are released when ready.[27][28]
In 2015, the Oakland Zoo began a rehabilitation project of the frog in order to fuel efforts to save the species.[29] 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.[30] 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.[31][32]
The mountain yellow-legged frog (Rana muscosa), also known as the southern mountain yellow-legged frog, is a species of true frog endemic to California in the United States. It occurs in the San Jacinto Mountains, San Bernardino Mountains, and San Gabriel Mountains in Southern California and the Southern Sierra Nevada. It is a federally listed endangered species, 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. The mountains separating the headwaters of the South Fork and Middle Fork of the Kings River mark the boundary between the ranges of the two species.
La rana de montaña de patas amarillas (Rana muscosa) es una especie de anfibio anuro de la familia Ranidae. Se trata de una pequeña rana de unos 5 a 7,5 cm. La parte baja de su abdomen y la parte de abajo de sus patas traseras es de color amarillo o naranja, y tiene un color amarillento o rojizo en su dorso, con puntos o manchas negras, o marrones. Los especímenes jóvenes tienen menos color bajo sus patas. Cuando se las manipula huelen a ajo. Se distribuye por el sur de California. Estas ranas prefieren los hábitat de lagos o arroyos de montaña.
La rana de montaña de patas amarillas (Rana muscosa) es una especie de anfibio anuro de la familia Ranidae. Se trata de una pequeña rana de unos 5 a 7,5 cm. La parte baja de su abdomen y la parte de abajo de sus patas traseras es de color amarillo o naranja, y tiene un color amarillento o rojizo en su dorso, con puntos o manchas negras, o marrones. Los especímenes jóvenes tienen menos color bajo sus patas. Cuando se las manipula huelen a ajo. Se distribuye por el sur de California. Estas ranas prefieren los hábitat de lagos o arroyos de montaña.
Rana muscosa Rana generoko animalia da. Anfibioen barruko Ranidae familian sailkatuta dago, Anura ordenan.
Rana muscosa, la Grenouille des montagnes à pattes jaunes, est une espèce d'amphibiens de la famille des Ranidae[1].
Cette espèce est endémique du Sud de la Californie aux États-Unis. Elle est présente entre 370 et 2 290 m d'altitude dans la sierra Nevada, les monts San Gabriel, San Bernardino et San Jacinto[1],[2], et donc dans les contés de San Diego, de Riverside, de Los Angeles et de San Bernardino.
Cette espèce vit dans les prairies humides, au bord des cours d'eau et des lacs[3].
Rana muscosa mesure de 50 à 75 mm. Son dos est jaunâtre ou rougeâtre avec une pigmentation ou des taches noires ou brunes. Son abdomen et le dessous de ses pattes postérieures est jaune ou orange. Les jeunes ont les pattes moins colorées[3].
Rana muscosa, la Grenouille des montagnes à pattes jaunes, est une espèce d'amphibiens de la famille des Ranidae.
Rana muscosa [1] é unha especie de ránido endémica de California. Vive nas Montañas de San Jacinto, Montañas de San Bernardino e Montañas de San Gabriel do sur de California e no sur de Sierra Nevada. Está na lista federal de especies en perigo.[2]
As poboacións de R. muscosa do norte de Sierra Nevada foron redescritas como unha nova especie, co nome Rana sierrae.[2] As montañas que separan as cabeceiras dos ríos de South Fork e Middle Fork do río Kings marcan a fronteira entre as áreas de distribución das dúas especies.[1]
Rana muscosa mide de 4 a 8,9 cm de longo. A súa cor e debuxo son variables. É amarelada, acastañada ou oliva con marcas negras e marróns. O seu nome específico, muscosa, significa 'musgosa' en latín, inspirado pola súa coloración que lembra os musgos. Pode ter coxas amarelas ou laranxas. Cando se colle na man emite un cheiro defensivo que lembra ao do allo.[3]
Vive en regatos de montaña, lagos e ribeiras de lagos, ríos e lagoas, preferindo as áreas solleiras. Raramente sae da auga e pode permanecer mergullada durante longo tempo, probablemente por intercambio gasoso cutáneo. Os cágados necesitan un hábitat de auga permanente polo menos durante dous anos mentres se desenvolven. Detectouse a presenza desta ra en alturas entre 370 e 2.300 m no sur de California.[1]
Emerxe do seu sitio de invernada pouco despois da fusión das neves. A súa estación reprodutora empeza unha vez que pasa o período co fluxo de fusión máis alto, aproximadamente de marzo a maio na parte sur da súa área, e ata xullo nas altas montañas do norte. A fertilización é externa e o grupo de ovos é asegurado á vexetaión nunha corrente de auga ou ás veces poden deixalo flotando libremente en augas tranquilas. Os xuvenís poden ser cágados durante 3 ou 4 anos antes de sufrir a metamorfose.[3]
Esta especie carece de saco vocal. A súa chamada é áspera, elevándose ao final. Durante o día fai as chamadas debaixo da auga.[3]
Aliméntase de insectos como escaravellos, formigas, abellas, avespas, moscas e libélulas. Tamén pode comer cágados.[3]
É unha especie en perigo segundo a Lei de especies en perigo de EUA. A Unión Internacional para a Conservación da Natureza (IUCN) tamén a ten na súa lista de especies en perigo.[1] O seu status de conservación NatureServe é en risco (imperiled).[4]
Aínda que antes era unha especie común, Rana muscosa estivo ausente de gran parte da súa área nativa desde a década de 1970. Nos últimos cen anos o 90% das súas poboacións foron eliminadas.[5] Esta ra localizárase en 166 lugares das montañas do sur de California, pero en 2007 só quedaban en sete ou oito.[1] O descubrimento en 2009 de R. muscosa en dous lugares do Bosque Nacional de San Bernardino foi unha boa nova.[6] Agora está representada en Sierra Nevada por tres ou catro poboacións.[1] O seu declive atribúese a moitos factores, como as especies introducidas de peixes como a troita, gando que pasta,[7] o fungo quitridio infeccioso Batrachochitridium[8] e probablemente pesticidas, seca e radiación ultravioleta.[7]
As troitas foron introducidas en lagos e ríos de Sierra Nevada a finais da década de 1800 para incrementar a pesca recreativa na área. O peixe come os cágados como unha presa principal. As troitas introducidas cambiaron a distribución de varias especies nativas nos ecosistemas locais.[5] Despois da eliminación de peixes de varios lagos, a ra reapareceu e as súas poboacións incrementáronse.[5] Despois empezou a espallarse a outros hábitats axeitados próximos.[9]
O declive desta ra na súa área de distribución histórica foi asociada coa difusión de pesticidas desde áreas agrícolas.[10][11] Os espécimes que foron reintroducidos en corpos de auga dos que se retiraron os peixes non conseguiron sobrevivir e as análises realizadas atoparon pesticidas nos seus tecidos.[12] Os pesticidas son considerados por algunhas autoridades como unha ameaza maior para as ras que as troitas.[13] O papel relativo que xogan os pesticidas e os peixes introducidos no declive das ras aínda se debate e a perda de R. muscosa na súa antiga área foi probablemente influída por múltiples factores.[12]
Esta especie é un dos moitos anfibios afectados pola enfermidade fúnxica quitridiomicose. Fixéronse amplas investigacións sobre a bioloxía do fungo causante e como impedir o declive nas poboacións de anfibios.[8] O fungo ataca as áreas queratinizadas do corpo das ras. Os cágados non están gravemente afectados porque as súas únicas partes fortemente queratinizadas son as súas vaíñas mandibulares e filas de dentes.[14] A infección dos cágados pode identificarse por cambios na pigmentación desas partes.[15] Os adultos teñen unha pel rica en queratina e sofren peores infeccións.
Fixéronse estudos nos que ras adultas sas foron expostas á compaña de ras infectadas durante polo menos dúas semanas e desenvolveron a enfermidade. O contaxio require máis tempo nos cágados, xeralmente unhas sete semanas.[15] As ras poden estar predispostas á infección se os seus sistemas inmunitarios están debilitados ou por outros factores, como os pesticidas.[16] Os estudos realizados indican que R. muscosa é de forma natural máis susceptible ao fungo quitridio que moitas outras ras.[17]
A primeira reprodución en catividade con éxito destas ras ocorreu en 2009 cando se criaron tres cágados no Zoo de San Diego. Os traballadores conservacionistas do zoo planearon a liberación das ras sobreviventes da crianza en catividade na súa área nativa das Montañas de San Jacinto.[18][19]
En 2015 ras e cágados da especie foron reintroducidos en Fuller Mill Creek nas Montañas de San Bernardino e no Bosque Nacional de San Bernardino.[20] Foron cruzados e criados polo Centro Arnold e Mabel Beckman para a Investigación da Conservación en Escondido, California, unha das organizacións que se asociou co Instituto para a Investigación da Conservación do Zoo de San Diego (ICR) para salvar a especie da extinción.[20] O Zoo de Los Ángeles é tamén un asociado e actualmente alberga dous grupos de cágados recollidos na natureza en dúas localidades das Montañas de San Gabriel, ata que crezan dabondo como para que soporten a liberación en condicións naturais.[20]
En 2015, o Zoo de Oakland empezou un proxecto de rehabilitación da ra para axudar nos esforzos de salvar a especie.[21] Cada ano, recóllese un grupo de cágados dos seus lagos nativos de California e lévanse ao zoo. Alí, os cágados crecen ata ser ras novas, mentres que tamén se someten a un proceso de inoculación para volvelas inmunes ao fungo da quitridiomicose. Cando están xa listas, as ras xuvenís inmunes a este fungo quitridio son liberadas nos lagos de onde procedían. En 2016, o Zoo de Oakland liberou 53 espécimes en varios lagos nos Parques Nacionais do Canón do Kings e Sequoia.[22] O programa prevé liberar 130 individuos inoculados en lagos dos Parques Nacionais do Canón do Kings e Sequoia e do Bosque Nacional Inyo en 2017.
Rana muscosa é unha especie de ránido endémica de California. Vive nas Montañas de San Jacinto, Montañas de San Bernardino e Montañas de San Gabriel do sur de California e no sur de Sierra Nevada. Está na lista federal de especies en perigo.
As poboacións de R. muscosa do norte de Sierra Nevada foron redescritas como unha nova especie, co nome Rana sierrae. As montañas que separan as cabeceiras dos ríos de South Fork e Middle Fork do río Kings marcan a fronteira entre as áreas de distribución das dúas especies.
Rana muscosa is een kikker uit de familie echte kikkers of Ranidae.[2] De soort werd voor het eerst wetenschappelijk beschreven door Charles Lewis Camp in 1917. Oorspronkelijk werd de wetenschappelijke naam Rana boylii muscosa gebruikt.
De kleur is grijsgroen tot bruin met donkere groene of bruine vlekken en bijna zwarte kleine vlekjes op de onderzijde van de flanken. De twee huidplooien langs de zijkanten steken iets uit en de toppen van vingers en tenen zijn zwart. Het belangrijkste kenmerk is de gele tot oranje onderzijde van de achterpoten. Soms is ook het achterste deel van de buik geel tot oranje gekleurd. Deze kleuren dienen om vijanden af te schrikken bij een aanval; als de kikker wegspringt komt ineens de felle kleur tevoorschijn die een predator even kan doen aarzelen waardoor de kikker kan ontsnappen.
Rana muscosa leeft in het hoger gelegen deel van de Sierra Nevadabergketen in de Verenigde Staten.[3] De paring vindt plaats van mei tot augustus, vlak nadat de meertjes en stroompjes ijsvrij zijn. De zwart gepigmenteerde eitjes worden in kleine groepjes gelegd en aan waterplanten vastgeplakt.
Deze soort is dagactief en vangt kleine ongewervelden zoals insecten. Bij verstoring wordt een licht irriterende stof verspreidt die qua reuk aan knoflook doet denken. Ook de knoflookpad (Pelobates fuscus) kent een dergelijke verdediging, maar deze soort leeft in Europa.
Rana muscosa is een kikker uit de familie echte kikkers of Ranidae. De soort werd voor het eerst wetenschappelijk beschreven door Charles Lewis Camp in 1917. Oorspronkelijk werd de wetenschappelijke naam Rana boylii muscosa gebruikt.
Rana muscosa é uma pequena espécie de rã com um tamanho de 5 a 7,5 cm. A parte inferior de abdómen e a parte inferior das patas traseiras é de cor amarela ou laranja, e o dorso é de cor amarelada ou avermelhada, com manchas negras ou castanhas. Os juvenis são menos coloridos na parte de baixo das patas. Quando manuseadas, deitam cheiro a alho.
Estas rãs preferem os habitats lacustres ou riachos de montanha.
Rana muscosa é uma pequena espécie de rã com um tamanho de 5 a 7,5 cm. A parte inferior de abdómen e a parte inferior das patas traseiras é de cor amarela ou laranja, e o dorso é de cor amarelada ou avermelhada, com manchas negras ou castanhas. Os juvenis são menos coloridos na parte de baixo das patas. Quando manuseadas, deitam cheiro a alho.
Estas rãs preferem os habitats lacustres ou riachos de montanha.
黄腿山蛙（学名：Rana muscosa）是极危物种已列入美国联邦濒危物种（the federal Endangered Species List）和世界自然保护联盟濒危物种红色名录。[2]科学专家曾估计，目前在野外只剩下了122只黄腿山蛙。
2009年6月10日美国地质局的一组人员看到了黄腿山蛙。他们当时正在洛杉矶以南的一处地区搜寻。这处地段以前曾经有大量的黄腿山蛙，但是50年来一直没有人再见到过它们的踪影。两个星期过后，圣迭哥自然历史博物馆的一组人员在四公里以外的地方又看到了另一只黄腿山蛙。这种珍稀的青蛙一般不会四处活动，因此，科研人员相信，这意味着在新近看到的两只青蛙之间的小溪地带，可能生活着大批的这种青蛙。[3]
本文全部或部分内容来自美国联邦政府所属的美国之音网站。根据版权条款（英文）和有关美国政府作品版权的相关法律，其官方发布的内容属于公有领域。
黄腿山蛙（学名：Rana muscosa）是极危物种已列入美国联邦濒危物种（the federal Endangered Species List）和世界自然保护联盟濒危物种红色名录。科学专家曾估计，目前在野外只剩下了122只黄腿山蛙。
2009年6月10日美国地质局的一组人员看到了黄腿山蛙。他们当时正在洛杉矶以南的一处地区搜寻。这处地段以前曾经有大量的黄腿山蛙，但是50年来一直没有人再见到过它们的踪影。两个星期过后，圣迭哥自然历史博物馆的一组人员在四公里以外的地方又看到了另一只黄腿山蛙。这种珍稀的青蛙一般不会四处活动，因此，科研人员相信，这意味着在新近看到的两只青蛙之间的小溪地带，可能生活着大批的这种青蛙。
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