The importance of peripheral populations in the face of novel environmental change

Anthropogenically driven environmental change has imposed substantial
threats on biodiversity, including the emergence of infectious diseases
that have resulted in declines of wildlife globally. In response to
pathogen invasion, maintaining diversity within host populations across
heterogenous environments is essential to facilitating species
persistence. White-nose syndrome is an emerging fungal pathogen that has
caused mass mortalities of hibernating bats across North America. However,
in the Northeast, peripheral island populations of the Endangered northern
myotis (Myotis septentrionalis) appear to be persisting despite infection
while mainland populations in the core of the species range have
experienced sharp declines. Thus, this study investigated host and
environmental factors that may contribute to divergent population
responses. We compared patterns of pathogen exposure and infection
intensity between populations and documented the environmental conditions
and host activity patterns that may promote survival despite disease
invasion. For island populations, we found lower prevalence and less
severe infections, possibly due to a shorter hibernation duration compared
to the mainland, which may reduce time for disease progression. The
coastal region of northern myotis range may serve as habitat refugia that
enables this species to persist despite pathogen exposure; however,
conservation efforts could be critical to supporting species survival in
the long-term.