Interspecific competition in bats and diet shifts in response to White-Nose Syndrome

Since the introduction of white-nose syndrome (WNS) in North America,
numerous species of bat have dwindled in numbers. These declines observed
are often species-specific and thus provides opportunity for a natural
experiment to test for shifts in diet through relaxed resource
partitioning in bat communities post-introduction of WNS. Acoustic
monitoring at locations in Southern Ontario pre- (2009– 2011) and post-WNS
(2012–2014) introduction showed an increase in activity of big brown bats
(Eptesicus fuscus) corresponding to a decline in the activity of little
brown bats (Myotis lucifugus). Next-generation sequencing of bat stomachs
and guano in Southern Ontario before and after WNS allowed for the
characterization of diet changes of these species. Post-WNS, E. fuscus
consumed a wider breadth of prey and many of the insect species once
consumed by M. lucifugus, including several pest insects. These results
suggest that the introduction of WNS has resulted in relaxed interspecific
competition within these bat communities in Southern Ontario.