Data from: Higher fat stores contribute to persistence of little brown bat populations with white-nose syndrome

1. The persistence of populations declining from novel stressors depends,
in part, on their ability to respond by trait change via evolution or
plasticity. White-nose syndrome (WNS) has caused rapid declines in several
North America bat species by disrupting hibernation behavior, leading to
body fat depletion and starvation. However, some populations of Myotis
lucifugus now persist with WNS by unknown mechanisms. 2. We examined
whether persistence of M. lucifigus with WNS could be explained by
increased body fat in early winter, which would allow bats to tolerate the
increased energetic costs associated with WNS. We also investigated if
bats were escaping infection or resistant to infection as an alternative
mechanism explaining persistence. 3. We measured body fat in early and
late winter during initial WNS invasion and eight years later at six sites
where bats are now persisting. We also measured infection prevalence and
intensity in persisting populations. 4. Infection prevalence was not
significantly lower than observed in declining populations. However, at
two sites, infection loads were lower than observed in declining
populations. Body fat in early winter was significantly higher in four of
the six persisting populations than during WNS invasion. 5. Physiological
models of energy use indicated that these higher fat stores could reduce
WNS mortality by 58 - 70%. These results suggest that differences in fat
storage and infection dynamics have reduced the impacts of WNS in many
populations. Increases in body fat provide a potential mechanism for
management intervention to help conserve bat populations.