The effect of agricultural land use, climate and red fox on the relative reproductive potential of European brown hare (Lepus europaeus) in Southern Germany

• Brown hare densities in Southern Germany have stabilized during the last two decades. • The impact of temperature during the breeding season on brown hare populations was stronger than the effects of agricultural land use and potential effects of red fox predation. • Temperature during the main breeding season explained 45 % of the inter-annual variation of the reproductive potential of brown hares (Southern Germany, 2008–2024). • Nowadays the realized reproductive potential might be 31 % higher compared to the 1970s and 1980s. The monitoring of European brown hares in various federal states of Germany suggests that local populations might have stabilized during the last 20 years (since 2004). In this study we used detailed spatial data on agricultural land use in a study area of 408 ha in Southern Germany for a time span of 17 years (2008–2024) in which brown hare density was monitored in a standardized way twice in spring and twice in autumn via spotlight counts. By using a N-mixture model we derived estimates for the local population size. We then investigated whether the reproductive potential (i.e. the difference in hare numbers between autumn and spring divided by the number of hares in spring) of brown hare depended on temperature, precipitation (climate window analysis), agricultural land use practices and red fox predation. Temperature between the end of February and the beginning of June is the most important variable for our study area, explaining 45 % of the inter-annual variation of the reproductive potential of brown hares.