Distribution, Ecology, Life History, and Conservation Status of the Berry Cave Salamander (Gyrinophilus gulolineatus)

Berry Cave Salamanders (Gyrinophilus gulolineatus) are neotenic, stygobitic salamanders endemic to the Appalachian Valley and Ridge of eastern Tennessee, USA. We conducted surveys for G. gulolineatus from 2017–2019 to assess the status, locate new populations, and address knowledge gaps related to life history and population ecology required for conservation assessment. We confirmed the presence of G. gulolineatus at four of 11 historical sites, but we did not observe it at any additional caves. At the three known cave sites with greatest abundance, visual counts per survey ranged 0–19 salamanders in 2017–2019. There was no apparent trend in abundance at Berry Cave. Visual counts declined 65% since the mid-2000s at Meads Quarry Cave and 80% since the early 1980s at Mudflats Cave. Mark-recapture studies in 160-m of cave stream at Berry Cave in 2017–2018 and 900-m of cave stream at Meads Quarry Cave in 2008 yielded population size estimates that ranged from 34–78 and 15–65 individuals, respectively. We identified 13 existing or potential threats to populations. Habitat degradation and groundwater contamination represent the most evident threats to long-term viability. Based on our conservation assessments, we recommend a rank of Endangered under Red List criteria of the International Union for Conservation of Nature and Critically Imperiled-Imperiled (G1G2) under NatureServe criteria. In opposition to the recent U.S. Fish and Wildlife Service decision, we advocate that, at a minimum, G. gulolineatus remain a Candidate Species, and we offer recommendations for research, conservation, and management of this rare salamander.