Meeting Abstract
White-nose Syndrome is caused by a cutaneous infection with the fungus Pseudogymnoascus destructans (Pd). It is known to produce hibernation mortality rates of 75 – 98% in 4 bats: Myotis lucifugus, M. septentrionalis, M. sodalis, and Perimyotis subflavus. These high mortality rates are observed during the first 1-2 years after the arrival of P. destructans at a hibernation site and are caused by a 60% decrease in torpor bout duration, which results in a premature depletion of depot fat prior to spring. Little is known about the long-term effects of this fungus on torpor and mortality, thus we conducted a 9-year study on M. lucifugus at 2 of the hibernation sites where Pd first appeared in North America. The M. lucifugus hibernating at these sites one year after the arrival of Pd had: a) a mean torpor bout duration of 7.6 d, b) depleted depot fat reserves by March, and c) a mortality rate of 88-92%. The M. lucifugus hibernating at these sites 6-9 years after the arrival of Pd, in contrast, had: a) a mean torpor bout duration of 14.7 d, b) depot fat remaining in March, and c) a mortality rate of 50%. The number of M. lucifugus hibernating at these sites consistently increased since 2010 and is now 3.0-3.5 times greater than the number remaining after the winter of 2008-09. These findings indicate that this population of M. lucifugus has evolved mechanisms to hibernate normally in the presence of Pd, thus reducing their over-winter mortality rate.
