Data from: Large-scale recovery of an endangered amphibian despite ongoing exposure to multiple stressors

Amphibians are one of the most threatened animal groups, with 32% of
species at risk for extinction. Given this imperiled status, is the
disappearance of a large fraction of the Earth’s amphibians inevitable, or
are some declining species more resilient than is generally assumed? We
address this question in a species that is emblematic of many declining
amphibians, the endangered Sierra Nevada yellow-legged frog (Rana
sierrae). Based on >7,000 frog surveys conducted across Yosemite
National Park over a 20-y period, we show that, after decades of decline
and despite ongoing exposure to multiple stressors, including introduced
fish, the recently emerged disease chytridiomycosis, and pesticides, R.
sierrae abundance increased sevenfold during the study and at a rate of
11% per year. These increases occurred in hundreds of populations
throughout Yosemite, providing a rare example of amphibian recovery at an
ecologically relevant spatial scale. Results from a laboratory experiment
indicate that these increases may be in part because of reduced frog
susceptibility to chytridiomycosis. The disappearance of nonnative fish
from numerous water bodies after cessation of stocking also contributed to
the recovery. The large-scale increases in R. sierrae abundance that we
document suggest that, when habitats are relatively intact and stressors
are reduced in their importance by active management or species’ adaptive
responses, declines of some amphibians may be partially reversible, at
least at a regional scale. Other studies conducted over similarly large
temporal and spatial scales are critically needed to provide insight and
generality about the reversibility of amphibian declines at a global
scale.