Santa Cruz Island Salamanders: comparing habitats and fungal infection of sympatric endemics

Santa Cruz Island, the largest of the California Channel Islands, harbors two congeneric and sympatric slender salamanders (genus Batrachoseps): the island-endemic B. pacificus and B. nigriventris. No comparative study of these populations has been conducted. Over two years, we performed habitat transect and coverboard surveys on the island, documenting microhabitat characteristics of individuals encountered, and collecting morphometric data. Animals were also swabbed for the chytrid fungal pathogen Batrachochytrium dendrobatidis (Bd), a global and devastating disease. Preliminary results indicate that populations are not uniform across the island, and that the two species differ in body size and in the thermal and humidity conditions associated with their occurrence. Additionally, Bd has been detected in a subset of individuals. These findings suggest possible habitat partitioning between the two species and raise concern about disease dynamics in this isolated island population.