CHYTRIDIOMYCOSIS IMMUNE PRIMING AS A TOOL FOR RANA SIERRAE POPULATION RECOVERY?

Rachel Bauer; US Forest Service; rachel.bauer@usda.gov; Grace Henke, Colin Dillingham, Abigail Marshall, Sandra Mayne, Grace Henke

The chytrid fungus Batrachochytrium dendrobatidis (Bd), and related chytridiomycosis disease, has led to dramatic population declines and extinction of amphibian species worldwide. The Sierra Nevada yellow-legged frog (Rana sierrae) is highly susceptible to Bd and natural recovery of populations where Bd has become established in the ecosystem is limited. Currently, Bd-related disease mitigation strategies primarily focus on preventing spread of the pathogen. There is a need to better understand the dynamics of amphibian responses to the pathogen and increase the tools available to managers to assist population recovery. Here we explore the idea of immune priming as a tool for increasing the resilience of R. sierrae to Bd. In 2022, the US Forest Service in collaboration with the San Franscisco Zoo, utilized captive-reared R. sierrae to apply experimental immune priming for chytridiomycosis. Zoo-reared frogs were inoculated with Bd and then treated with the antifungal medication itraconazole prior to being released back into their wild habitat where Bd is present. Preliminary results of monitoring chytrid infection levels for individuals recaptured during surveys found similar infection levels of Bd between the experimental and control group in the first year. Ongoing monitoring will explore potential longer-term effects of immune priming.

Poster Session