Modelling the potential efficacy of treatments for white-nose syndrome in bats

1. The fungal disease white-nose syndrome (WNS) has caused mass mortality in some species of North American bats during hibernation.

2. We use population viability models to test if a hypothetical WNS treatment or management action could facilitate the recovery of WNS-affected little brown myotis (Myotis lucifugus) populations. We modelled scenarios altering three parameters: (1) WNS severity (population growth rate of WNS-affected populations; λWNS); (2) proportion of population treated; and (3) treatment improvement in winter survival (TIWS).

3. Our models predict that a treatment or management action that targets an entire population with a TIWS of 40% (the average TIWS in bat trials to date) will cause a population to stabilize or increase if WNS causes an annual decline of less than 70% (i.e. λWNS>=0.30). However, for severe WNS (λWNS=0.10), the TIWS must be at least 54% to cause the population to stabilize or increase. Where only a proportion of a WNS-affected populatio...