His 2016 study, published in the Proceedings of the National Academy of Sciences, found the number of frogs in the park had increased sevenfold in 20 years. Imagine a mountain lake where each step you take causes dozens of frogs to leap into the water. That used to be the rule in California’s Sierra Nevada. According toan Associated Press report on KQED, researcher Roland Knapp documented the return of the Sierra Nevada yellow-legged frog.
Disease came later. It is called chytridiomycosis, and a fungus causes it. It has led to the extinction of hundreds of frog populations. It has spread to most of the yellow-legged frog populations in Yosemite. Knapp called the rebound an important milestone. Elsewhere in its range, the frog remained scarce. It is still protected as a federally endangered species . This frog shows that even a severely imperiled species can recover. Grasso hopes the frog could one day come off the list. Researchers note that better management and the frog’s resistance to the fungus may be able to reverse amphibian declines elsewhere. Nature and visitors can share the same park.
Scientists note that trout and then disease took the frog out of about 90% of its native habitat in the Sierra. The same report said the rebound was limited to Yosemite, which holds 13 percent of the frog’s historical habitat in the Sierra. Today, some 250 water bodies and 800 miles of rivers and streams in Yosemite still contain non-native fish.
The park service says it has spread throughout the Sierra Nevada since the 1970s. He said the frog has a long way to go to reach its old numbers. Rob Grasso, the park’s aquatic ecologist, says species rarely come off the endangered list. Fishing is still available at many sites in the park, according to the park service.
