Impact of human disturbance, density, and environmental conditions on the survival probabilities of pipistrelle bat (Pipistrellus pipistrellus)

Abstract

Natural and anthropogenic disturbances can strongly impact population dynamics of species and are often responsible for zoonotic emerging infectious diseases. However, long-term studies on the demographic consequences of human disturbances are unusual. We used 6 years (1995-2000) of mark-recapture data to investigate how climatic conditions, human disturbance and density affect sex- and age-specific apparent survival probabilities of the pipistrelle bat (Pipistrellus pipistrellus, Schreber 1774) in a maternity colony. Our study demonstrated that density played an important role in population dynamics of pipistrelle bat and that its effect differed with respect to age and sex. Notably, human disturbance caused a strong decline of adult female survival, suggesting that perturbations have important consequences in bat-colony dynamics. Juvenile female survival was negatively influenced by density, being considerably lower in high densities. In contrast, juvenile and adult males were apparently not affected as they had constant survival probabilities. Although climatic factors can markedly affect population dynamics of temperate insectivorous bats, in this study, the weather conditions did not influence the survival rates of pipistrelle bats. We provide the first report that demonstrates the density-dependent effect on bat survival. That is especially relevant to better understanding of the bat-population dynamics and to evaluate the consequences of human disturbance and their potential changes in the maternity colony structure. © 2014 The Society of Population Ecology and Springer Japan.