An army of rare frogs were transported from the Oakland Zoo to Sequoia and Kings Canyon National Park in an ongoing effort to safe the species from extinction. The release marked the 1000th frog released by Oakland Zoo and a decade of efforts to save this species.
Native yellow-legged frogs used to be a prominent species throughout the Sierra-Nevada Mountain Range, but the population has seen a decline of more than 90 percent in the past decade due to non-native predators and chytrid, a skin fungus that thickens the frog’s skin so they can’t breathe. The disease is highly contagious and can wipe out populations in a matter of weeks.
Frogs play a crucial role in the ecosystem, as prey for larger animals, predators of insects, and excellent bioindicators for environmental stressors, according to a news release from the Oakland Zoo. “Frogs once were a keystone species in high elevation lakes but chytrid and other factors reduced their populations significantly.”
Researchers scoured lakes in Yosemite National Park for any remaining frogs, and remarkably found that some of the frogs had evolved a resistance to chytrid fungus.
A project led by the University of California, the Oakland Zoo, and others studies the natural resistance of survivor populations, investigating potential antifungal skin bacteria, antifungal skin peptides, and even genetic resistance.
At the Oakland Zoo, they are developing an inoculation procedure which includes “infecting the frogs with a controlled amount of fungus and allowing their immune systems time to recognize the pathogen before treating them with antifungal baths to cure them,” according to their webpage. “We hope that this controlled infection will allow their immune systems to recognize and fight off the fungus if they encounter it again after they have been released to the wild.”
The project is major milestone, not only for the yellow-legged frog but also for other amphibian species that are being affected world-wide by the chytrid fungus.
