The Sierra Nevada yellow - legged salientian has been declining for over a century . border ever closer to extinction , things have not looked unspoiled for the footling amphibious aircraft , yet its fortunes might just be changing . Surveys over the last two decades have found that population in some regionsare inexplicably increasing , providing hope that the specie may not yet be relinquish to the chronicle books .
The native amphibians have really been facing two fronts of attack . First , they had to contend with the non - aboriginal trout that were introduced in the late nineteenth hundred for fishing . These ravenous predators pop to raven the eggs and polliwog of the frog , post the population into a tailspin . But things really hit the proverbial fan in the 1970s , as the deadly chytrid fungus hit the Sierras , wiping out the frogsin over 90 percentof their home ground .
What was once the most abundant amphibian in the mountain range became a rarity getting rarer . But over the last two decades , the Gaul has experienced an unprecedented replication . develop in population by around 11 percent a year , there are now think to be seven times as many toad frog than when researcher first started surveying them in Yosemite in the nineties . Yet , curiously , the invasive fish still float in the rivers and the fungus has not gone aside , score the amphibious vehicle ' comeback unexpected .
It could be potential the anuran have evolved a resistance to the fungus that has been wiping out other species around the globe , according to the researchers in their theme published in theProceedings of the National Academy of Sciences . If so , this raises the interesting theory that other population of amphibian , if give sufficient shelter and help , may be able to break immunity to the fungus by themselves . So far , though , only the population in Yosemite have been find to be growing .
Further exam find that those frogs that had been up against the disease for the longest period of time were also those showing the greatest resistance , endorse up the feeling that the amphibians can indeed evolve to fight the fungus . Many have suggested that this could happen , but others are conservative about such results .
The Sierra Nevada icteric - legged frog may well be able to evolve resistance , but this does n’t mean that all species of amphibian will have the same ability , especially reckon the speed at which the fungus can decimate populations .
