Meeting Abstract
White-nose syndrome (WNS) has decimated populations of hibernating bats in the U.S. Among the bat species affected by WNS, Eptesicus fuscus (big brown bat) appear to be the least affected while M. lucifugus (little brown myotis) appear to be one of the most affected. Understanding the energetic cost of immune function in M. lucifugus and E. fuscus is important for understanding the immune response and recovery of bats to WNS. We examined basal metabolic rate (BMR), an important measure of energy expenditure, and bacterial killing ability of blood (BKA), an important measure of innate immune ability, in both species. WNS can damage a bat’s wing, which can impact flight cost and energy use. Additionally, the extent of wing damage reflects the course of immune response and recovery to the Pseudogymnoascus destructans fungus, the cause of WNS. We hypothesized that wing damage would be positively correlated with BMR. After accounting for body mass, little brown myotis with moderate wing damage had a higher BMR than little brown myotis with both minimal and severe damage. Thus, wing damage due to WNS is energetically costly in little brown myotis. However, in little brown myotis, BMR was highest during the recovery phase to wing damage (when damage is moderate), but not during the phase of active exclusion of fungus from wing tissue (when damage is severe). We found BKA was positively correlated with the extent of wing damage in little brown myotis. Thus, complement protein activity is greatest during the active exclusion of fungus. Our initial analysis suggests that the impact of WNS on BMR and BKA is less in big brown bats than in little brown myotis.
