Winter habitats of bats in Texas

PLoS One. 2019 Aug 8;14(8):e0220839. doi: 10.1371/journal.pone.0220839. eCollection 2019.

Abstract

Few studies have described winter microclimate selection by bats in the southern United States. This is of particular importance as the cold-adapted fungus, Pseudogymnoascus destructans, which causes the fatal bat disease white-nose syndrome (WNS), continues to spread into southern United States. To better understand the suitability of winter bat habitats for the growth of P. destructans in this region, we collected roost temperature and vapor pressure deficit from 97 hibernacula in six ecoregions in Texas during winter 2016-17 and 2017-18. We also measured skin temperature of Rafinesque's big-eared bats (Corynorhinus townsendii), Townsend's big-eared bats (C. townsendii), big-brown bats (Eptesicus fuscus), southeastern myotis (Myotis austroriparius), cave myotis (M. velifer), tri-colored bats (Perimyotis subflavus), and Mexican free-tailed bats (Tadarida brasiliensis) during hibernation to study their use of torpor in these habitats. We found that temperatures within hibernacula were strongly correlated with external air temperatures and were often within the optimal range of temperatures for P. destructans growth. Hibernacula and skin temperatures differed among species, with Rafinesque's big-eared bats, southeastern myotis, and Mexican free-tailed bats occupying warmer microclimates and having higher torpid skin temperatures. For species that were broadly distributed throughout Texas, hibernacula and skin temperatures differed within species by ecoregion; Tri-colored bats and cave myotis in colder, northern regions occupied colder microclimates within hibernacula and exhibited colder skin temperatures, than individuals of the same species in warmer, southern regions. These data illustrate the variability in microclimates used as hibernacula by bats in Texas and suggest similar variation in susceptibility to WNS in the state. Thus, monitoring microclimates at winter roosts may help predict where WNS may develop, and where management efforts would be most effective.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Chiroptera / microbiology*
  • Ecosystem*
  • Hibernation
  • Mycoses / etiology*
  • Seasons*
  • Skin Temperature
  • Species Specificity
  • Texas
  • Torpor

Grants and funding

This work was funded by the U.S. Fish and Wildlife Service’s State Wildlife Grant Program (CFDA# 15.611) as administered by Texas Parks and Wildlife Department, https://tpwd.texas.gov/ and the U.S. Fish and Wildlife Service (CFDA# 15.657), https://www.fws.gov/ (MLM, BLP). Additional funding support was provided by the Fightwns ‘Micro Grants for Microbats’, https://www.fightwns.org/, Texas Ecolab research grants, https://texasecolab.org/, and National Speleological Society WNS Rapid Response Grant, https://caves.org/WNS/Rapid_Response.shtml (BLP, MBM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.