DISTRIBUTION, NATURAL HISTORY, AND CONSERVATION STATUS OF THE RELICTUAL SLENDER SALAMANDER (BATRACHOSEPS RELICTUS)

The salamander species Batrachoseps relictus (Relictual Slender Salamander) is a candidate for listing as federally endangered. When initially described, this species was thought to be wide-ranging, occurring along both the coast and in the Sierra Nevada of California. However, molecular data revealed that B. relictus is a microendemic species restricted to a single mountain at the southern end of the Sierra Nevada. The natural history of this species is poorly known. Through extensive field work on Breckenridge Mountain, California, we have discovered 10 new populations since 2019, increasing the number of known extant populations to 13. We have also collected data on habitat, abundance, and life history. We seldom observed B. relictus in terrestrial microhabitats typical of the genus Batrachoseps and confirmed historic reports stating that it can be abundant in aquatic habitats. Oviposition takes place in these habitats in spring. Based on these life history and habitat observations, we reassess the threats facing this species and make recommendations for monitoring and land management, which include continued surveillance for amphibian chytrid fungus (Batrachochytrium dendrobatids, Bd), development of an eDNA survey approach, and the physical protection of sensitive microhabitats.