Data from: Activity patterns during the mating season predict sex-biased infections in an emerging fungal disease

Mating dynamics can govern species impacts from rapid global change by
influencing population rates of growth and adaptation, as well as
individual traits that affect mortality risks from novel pressures. Here,
we examined sex differences in the activity of Myotis lucifugus during
their mating season, which coincides with exposure to the lethal fungal
pathogen (Pseudogymnoascus destructans) that causes white-nose syndrome.
We expected differences in activity between sexes to modify seasonal P.
destructans dynamics as the pathogen can replicate only at the cool
temperatures at which bats hibernate. We used passive antenna systems
installed at the entrances of hibernacula and PIT tags to characterize
activity patterns of bats. We also measured pathogen loads on bats during
the autumn mating and early hibernation periods to assess how infection
changed according to host phenology. We found that females spent fewer
days active during autumn, arrived after males, and were primarily active
on the warmest nights. Males remained highly active throughout the mating
season and later in autumn than females. Importantly, differences in
phenology corresponded to higher pathogen loads on females during early
hibernation as male activity, and thus warm body temperatures, inhibit
pathogen growth. Differences in activity between sexes and in the
transition from swarm to hibernation likely reflect males maximizing their
mating opportunities while females conserve energy to meet the cost of
spring migration and reproduction. More broadly, our results show how
activity during the mating season and phenology can contribute to
sex-biased impacts of a novel disease and highlight the value of
understanding species’ mating systems to anticipate the impacts of
environmental change.