Découverte et caractérisation de places de chants de Vespertilion bicolore (Vespertilio murinus Linnaeus, 1758) dans le Massif Central (France)

The parti-coloured bat (Vespertilio murinus Linnaeus, 1758) is a little-known species in France, where it is found at the southwestern edge of its range. Male colonies and autumn mating display song are known in the Vosges mountains, near Germany, but its presence elsewhere is poorly documented. Following the discovery in 2023 of the second autumn mating display site of the species in the Massif Central, 45 passive bat acoustic sampling sites and five active bat acoustic sampling sites were set up from early September 2025 to mid-January 2026. Only rock walls and human constructions were targeted and sampling effort was equivalent. Recordings were analyzed using automatic identification software and manually verified. The study identified 15 mating display sites located between 428 and 1 472 meters above sea level. They remained active from late September to mid-December. They were positioned both on vertical rock walls and human constructions such as village or viaduct but mating activity was five times greater in rocky environments, which are the main very high vertical structures. These results suggest that Vespertilio murinus is fairly common during the mating season in the Massif Central and these mountains are an integral part of its hibernation range. The species would therefore have gone largely unnoticed until now during this period due to a lack of targeted surveys. It represents a new issue to be taken into account in land use planning policies. Seven mating display sites of this species highly sensitive to wind turbines are located less than 10 kilometers from a wind farm. Its significant presence in rock walls will also need to be considered in future cliff use planning.