Sex-differences of survival and seasonal dispersal in a meta-population of greater horseshoe bats

Demographic parameters such as survival and dispersal play a significant role in shaping population dynamics and genetic structure. However, dispersal remains difficult to estimate in natural populations, as it requires extensive individual sampling and monitoring in the landscape. We conducted a five-year capture-mark-recapture (CMR) study of Rhinolophus ferrumequinum in Nouvelle Aquitaine, France, monitoring 6673 individuals across 302 summer and winter roosts. For the first time in this species, we estimated seasonal survival and dispersal for both sexes using CMR models. We found high average adult survivals, with males displaying lower survival than females. Interestingly, both sexes showed high fidelity to summer or winter roosts with no strong marked differences between sexes. Strikingly, we found cues that females travelled on average longer distances than males to reach hibernation sites, challenging previous findings that dispersal is strongly male-biased in this species. Despite limited dispersal of both males and females, previous genetic studies have reported weak spatial genetic structure, suggesting that mating outside maternity colonies maintains gene flow. Our study highlights the importance of studying the full annual cycle monitoring in bats and supports conservation strategies that protect both maternity and hibernation roosts, as well as the landscape connectivity that enables seasonal movements.