Diet of the insectivorous bat Myotis emarginatus

In the face of human-associated massive arthropods decline, we aimed to study the diet and its spatio-temporal variations, the hunting style, the foraging habitat and finally the pest consumption of an insectivorous European bat species, using as model the Geoffroy bat, Myotis emarginatus. To achieve these goals, we monitored 6 roosting colonies in Wallonia (Belgium) at 3 temporal sampling points during the breeding season, by means of metabarcoding of DNA extracted from faeces. The study area corresponds to the northern range limit of this bat species, where, despite recovery in population size in the last decades, a combination of insular distribution and low genetic diversity makes it especially vulnerable. As a matter of fact, the Belgian Red List classifies the species as Near Threatened, a status that therefore merits a specific attention. We also selected the Geoffroy bat as it was reported foraging in cluttered environments such as woodlands but also visiting cowsheds, enabling us to assess whether it is an ally of forest managers and farmers through pest consumption. Our focus on this species has finally been driven by the current lack of study on its diet at the northern edge of its distribution, embracing a wide spatio-temporal scale and using the most advanced genetic tools. Indeed, only a handful of research incorporated high-throughput sequencing to investigate M. emarginatus prey spectrum. Furthermore, the few cases that did so were restricted to the Mediterranean or Atlantic climate, while entomofauna communities are expected to widely differ under the predominant temperate climate occurring in Belgium.