Growth, survival, longevity, and population size of the Big Mouth Cave salamander (Gyrinophilus palleucus necturoides) from the type locality in Grundy County, Tennessee, USA

Copeia
By: , and 

Links

Abstract

Salamander species that live entirely in subterranean habitats have evolved adaptations that allow them to cope with perpetual darkness and limited energy resources. We conducted a 26-month mark–recapture study to better understand the individual growth and demography of a population of the Big Mouth Cave Salamander (Gyrinophilus palleucus necturoides). We employed a growth model to estimate growth rates, age at sexual maturity, and longevity, and an open population model to estimate population size, density, detectability, and survival rates. Furthermore, we examined cover use and evidence of potential predation. Individuals probably reach sexual maturity in 3–5 years and live at least nine years. Survival rates were generally high (>75%) but declined during the study. More than 30% of captured salamanders had regenerating tails or tail damage, which presumably represent predation attempts by conspecifics or crayfishes. Most salamanders (>90%) were found under cover (e.g., rocks, trash, decaying plant material). Based on 11 surveys during the study, population size estimates ranged from 21 to 104 individuals in the ca. 710 m2 study area. Previous surveys indicated that this population experienced a significant decline from the early 1970s through the 1990s, perhaps related to silvicultural and agricultural practices. However, our data suggest that this population has either recovered or stabilized during the past 20 years. Differences in relative abundance between early surveys and our survey could be associated with differences in survey methods or sampling conditions rather than an increase in population size. Regardless, our study demonstrates that this population is larger than previously thought and is in no immediate risk of extirpation, though it does appear to exhibit higher rates of predation than expected for a species believed to be an apex predator of subterranean food webs.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Growth, survival, longevity, and population size of the Big Mouth Cave salamander (Gyrinophilus palleucus necturoides) from the type locality in Grundy County, Tennessee, USA
Series title Copeia
DOI 10.1643/OT-14-197
Volume 104
Issue 1
Year Published 2016
Language English
Publisher The American Society of Ichthyologists and Herpetologists
Contributing office(s) Wetland and Aquatic Research Center
Description 7 p.
First page 35
Last page 41
Country United States
State Tennessee
County Grundy County
Online Only (Y/N) N
Additional Online Files (Y/N) N