Introduction

Winter hibernation is assumed to be a period of near-complete immobility for bats. Hibernacula were thought to function as stable refuges where individuals remained for months at a time, conserving energy until spring. However, emerging evidence suggests a more dynamic reality. Some bats are moving between hibernacula during winter. These flights are inherently risky, exposing bats to predators and freezing temperatures when food is unavailable. Yet despite these risks, movements appear to occur. 

So, we asked the question. Why would bats leave the relatively safety of their hibernaculum during their most energetically constrained period to move to a different hibernaculum?

Objectives

To answer this question, we are combining traditional winter census surveys with an enhanced individual-based marking system. Each bat we mark receives a lightweight, uniquely numbered aluminum forearm band for long-term identification. Additionally, I developed a custom anodizing process that adds color to the bands to increase visibility and rapidly determine the site of origin of each bat without requiring repeated recapture. Each hibernaculum is assigned a distinct band color while retaining permanent numeric identification.

Understanding overwinter movement dynamics is critical for wildlife management. If hibernacula function not as isolated refuges but as connected nodes within a broader network, then conservation strategies must account for connectivity, disease spread, and the spatial structure of recovery. This work provides the empirical foundation for adaptive management decisions aimed at sustaining bat populations under ongoing environmental and disease pressures.