Possible microclimate benefits of roost site selection in the Red Bat, Lasiurus borealis, in mixed mesophytic forests of Kentucky

Avoidance of diurnal predators is considered a primary selection factor influencing the choice of roosting sites by Red Bats (Lasiurus borealis), as this species is cryptically colored and difficult to observe in diurnal roosts. Other benefits to Red Bats resulting from choice of roosting sites, such as lowered energy expenditures due to more stable microclimates, have not been explored. We compared the thermal environment within diurnal roosting sites of Red Bats to other locations in the habitat where the bats would be potentially subject to fluctuations in temperature extremes. Data indicated that roosting sites of Red Bats had significantly lower overall average temperatures, overall variance in temperatures, average diurnal temperatures, and variance in diurnal temperatures than other locations in the habitat, with no difference observed for any nocturnal temperature variable. These results suggest that Red Bats roosting in forest habitats may gain a thermal advantage by selecting diurnal roosting sites that ameliorate variability and extremes in temperature.