New paper published in Ecosphere

A paper entitled “Disease and climate effects on individuals drive post-reintroduction population dynamics of an endangered amphibian” by Max and Roland was published in Ecosphere today. The accompanying UCSB story is available here. Although developed for mountain yellow-legged frogs, the hierarchical Bayesian hidden Markov model they developed might be applicable to other species impacted by the amphibian chytrid fungus. 

Frogs make an unexpected recovery

In this new video, UCSB videographer Spencer Bruttig talks to Roland during a visit to one of his Yosemite study sites and gets the latest on the outcome of frog conservation efforts there. Amazingly, despite all of the challenges the Sierra Nevada yellow-legged frog has faced during the past century, the frogs are making a remarkable comeback. Hear about this exciting turn of events from someone who witnessed the frogs’ decline and now the beginning of their recovery.

Frog rescue in Yosemite National Park

Adult Sierra Nevada yellow-legged frog (Rana sierrae)

In the Sierra Nevada, the winter of 2015-2016 was one of the driest on record. During the following summer, a habitat in Yosemite National Park containing Sierra Nevada yellow-legged frogs slowly dried up. Just before the last pools dried, Yosemite mounted a rescue of the tadpoles stranded in the shrinking pools. Several thousand tadpoles were collected and flown via helicopter to a lake upstream in the watershed. This video shows the rescue in action.

Ecological consequences of frog declines

Read the new paper here. Published today in the journal Ecosphere, Tom, Roland, and Cherie Briggs (UC Santa Barbara) describe some of the ways in which mountain yellow-legged frog declines impact alpine lake communities. Contrary to expectations, the large scale loss of these frogs is not associated with secondary extinctions or changes in structure and composition of the benthic macroinvertebrate community, which contains most of the prey and competitor species for frogs and tadpoles. Notably, these results differ from 1) the consequences of frog declines in other ecosystems, and 2) the consequences of fish introductions in the Sierra. Although impacts of frog declines on the taxa examined in this study were small, mountain yellow-legged frog declines are associated with secondary declines in other species, like gartersnakes.