Seasonality and interspecific temporal partitioning in a semiarid grassland bat assemblage of northwestern India

Abstract

Arid and semiarid environments of the world are characterized by extreme environmental changes that affect the availability of scarce, patchily distributed resources such as water. In response to these changes, animals migrate or partition resources to minimize competition, resulting in temporal patterns within assemblages across multiple scales. Here, we demonstrate that the winter dry season bat assemblage in a semiarid grassland of northwestern India exhibits seasonal changes and temporal avoidance between coexisting species. Using a passive acoustic monitoring framework to quantify activity patterns at different points in the season, we show that members of this assemblage (Rhinolophus lepidus and Tadarida aegyptiaca) exhibit seasonal differences in activity, being more frequently detected in the early and late parts of the dry season, respectively. Other species (Pipistrellus tenuis and Scotophilus heathii) do not exhibit seasonal changes in activity, but structure diel activity patterns, minimizing temporal overlap (and thus competition) at water bodies. These data, some of the first on bats from this region, demonstrate the complex temporal patterns structuring bat assemblages in arid and semiarid biomes. Our results hold promise both in understanding bat behavioral ecology and in long-term monitoring efforts.