Effects of the Chytrid fungus on the Tarahumara frog (Rana tarahumarae) in Arizona and Sonora, Mexico

Abstract

We conducted histological analyses on museum specimens collected 1975-1999 from 10 sites in Arizona and Sonora to test for the pathogenic chytrid fungus (Batrachochytrium dendrobatidis) in ranid frogs, focusing on the Tarahumara frog (Rana tarahumarae). During 1981-2000, frogs displaying disease signs were found in the field, and all of these we tested were infected with the chytrid pathogen. Population monitoring results at localities with the infection ranged from apparent disappearance, to decline and recovery, and, in some cases, apparent stability. One population was infected over a 17-year period without apparent population decline. Our results suggest that stress, notably cold, and possibly pollution, may influence disease severity. The presence of chytridiomycosis in Sonora was confirmed for R. tarahumarae (1982-1999) R. yavapaiensis (1999), R. magnaocularis (1985, 1999), and R. pustulosa (1985).

Parent Publication

• Connecting mountain islands and desert seas: Biodiversity and management of the Madrean Archipelago II

Citation

Hale, Stephen F.; Rosen, Philip C.; Jarchow, James L.; Bradley, Gregory A. 2005. Effects of the Chytrid fungus on the Tarahumara frog (Rana tarahumarae) in Arizona and Sonora, Mexico. In: Gottfried, Gerald J.; Gebow, Brooke S.; Eskew, Lane G.; Edminster, Carleton B., comps. Connecting mountain islands and desert seas: biodiversity and management of the Madrean Archipelago II. Proc. RMRS-P-36. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 407-411