Lonely Planet Writer

Yosemite yellow-legged frogs make giant leap towards survival

The endangered yellow-legged frog has made a giant leap towards survival after decades of attack from man, disease and pesticide.

Yellow-legged frog
Yellow-legged frog Image by USFS Region 5 / CC BY 2.0

Their decline began back in the 1950s when Californian wildlife authorities in the USA sought to improve their fish stocks by flying over Yosemite National Park and dropping off hatchery-raised trout. It was a delight for fishermen, reports the LA Times, but disaster for the distinctively marked frogs, residing in the same water but unable to compete for food with the hungry invaders. However, Science Daily says that despite the interference with its habitat, the yellow-legged frog has shown a remarkable recovery in the face of adversity. The amphibians got a little help along the way, as man tried to restore nature’s balance by beginning a process of dropping fist-sized frogs into the same waters where once they placed the voracious  trout.

Latest research from Roland Knapp, the UC Santa Barbara biologist and his fellow scientists show that frog numbers, across Yosemite, have jumped seven-fold or by 11% during the 20-year compilation of data there. Or as biologist at San Francisco University, Vance Vredenburg, puts it:  if frogs are “given room to thrive, they will.” The Rana sierrae has a reddish-brown colour on top, with yellow legs and underside, and has also had to face disease problems against the deadly chytrid fungus.

The LA Times explained that this causes the amphibians’ skin to thicken and interferes with their respiration and ability to absorb water. However, scientists are buoyed by the fact that the frogs appear to have also developed some sort of defence against the disease. Mr. Knapp said their findings prove that some species of frog “are remarkably resilient.” Their research also suggests, he added, that amphibian decline globally may be “at least partially reversible” provided it is done so with appropriate management.