Bat Conservation at Ruffner Mountain: An Update on Tricolored Bats

Tricolored Bats: Small and Vulnerable 

This tricolored bat (Perimyotis subflavus) is one of North America’s smallest bat species. These bats typically use caves, mines, or other subterranean environments for their winter roost to hibernate and often use large, hollow trees for roost and especially for their maternal/pupping roost during the summer. This wintering habit makes them susceptible to the disease White-nosed syndrome (WNS). WNS has caused severe mortality in populations of multiple bat species across the eastern United States. See whitenosesyndrome.org for more information. Tricolored bats have suffered declines of over 95% across much of their range, resulting in a once-common species being proposed for endangered status listing. 

Pseudogymnoascus destructans (Pd) is the fungus that causes WNS and was first documented in Albany, New York, in 2007 and then in Jefferson County, Alabama, in the tricolored bat population at Ruffner during a winter survey in 2017. Since that time, this population has been important for various studies to monitor and potentially find disease management solutions.

Encouraging Signs and Ongoing Research

In February 2025 we conducted a hibernation survey and documented 485 tricolored bats. This is the highest population number that we have documented in the hibernacula since 2018, which is a good sign for disease resistance. 

In March, we hosted three different research opportunities. We partnered with Alabama Department of Conservation and Natural Resources (DCNR) biologist Olivia Wilkes and a team from the University of Montana with Julie Weckworth researching Pd and tricolored bats. The team was surveying seven caves and mines with known bat populations in Alabama. Their goal was to collect data of potential Pd found on bats and the hibernacula environment, collecting genetic data from individual bats and photographing bat wings under a special UV light apparatus as well as recording temperature and humidity of the mine. We will repeat this process again this coming winter.

We also partnered with Pete Patavina, United States Fish and Wildlife Services (USFWS) Southeast WNS Coordinator, to collect Pd samples for Joseph Hoyt’s ongoing monitoring project at Virginia Tech as well as the third opportunity of the month to collect samples for Chris Cornelison’s work at Kennesaw State. Both of these projects are important for monitoring potential resistance and treatment of WNS in bats. Similarly to the UM study, these projects' goals were to collect potential Pd found on bats and the environment, collect genetic data from individual bats as well as record the temperature and humidity of the mine. We will also repeat this process again this coming winter.
‍

Written by: Jamie Nobles

Photo courtesy of: Jamie Nobles

‍