Individual Variation in Overwintering Strategies of the Great Evening Bat (Ia io) in Subtropical China

Abstract

Understanding how bats adapt their overwintering behavior to local environmental conditions is crucial for conservation, especially in subtropical regions where individual strategies remain poorly documented. We tracked six male great evening bats (Ia io) in Guizhou, China, using GPS and tri-axial accelerometry. All individuals remained within 30 km of their summer roosts, confirming a non-migratory overwintering strategy. However, striking individual variation was observed: two bats exhibited continuous torpor lasting over 60 days, while four employed flexible torpor with arousal on warmer nights. The probability of arousal increased by approximately 16% for every 1°C rise in ambient temperature. These results provide the first field-based evidence of individual-level behavioral flexibility in a subtropical bat species and highlight the need to protect critical overwintering roosts and incorporate climate-driven behavioral diversity into conservation planning.

Keywords

behavioral plasticity / climate change / GPS tracking / overwintering strategies / subtropical bats / torpor

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