Estimation of demographic fluctuations within a reproductive roost of Pipistrellus kuhlii inferred from capture-mark-recapture data

Abstract

Despite bats representing one fifth of all mammals, little is known about the ecology and the population status for many species belonging to this order. This is often a consequence of our poor knowledge of population densities and demographic parameters, bats being typically elusive subjects for ecological studies. Capture-mark-recapture studies provide important demographic and ecological data to fill up this information gap. In this study, we monitored animals and gathered data over five years from a reproductive roost of Kuhl's pipistrelle (Pipistrellus kuhlii Kuhl, 1817) located in a Natura 2000 site in north-west Italy. One-hundred-thirty-three individuals were captured and demographic parameters collected, including the annual survival probability for both young and adults, the recapture rates for different sex and age cohorts and the adult population size trend. The influence of environmental variables on the population was also assessed, highlighting the relevant impact of winter temperatures and spring rainfalls on individual survival ability. Notably, our study provides for the first time an estimation of the survival rate of adult females of Kuhl's pipistrelle, a crucial information for future design of studies related to this species' ecology and for informing conservation efforts.