European brown hare populations have declined during the last decades. Agricultural intensification has been identified as a relevant driver of this process and agri-environment schemes have been implemented to foster biodiversity in agricultural landscapes. Because species-specific outcomes of measures strongly depend on tailored design of the policy framework and the local management, while changing climate may pose additional challenges, policy and management need science-based information of which landscape composition should be promoted to achieve set biodiversity goals.

Here, we used direct observations of European brown hares over 20 years for evaluating the effects of landscape composition and weather conditions on European brown hare density. For the first time, our analysis compared the estimates of machine learning (gradient boosting machine) and linear mixed models in terms of importance of a wide range of explanatory variables for European brown hare densities and effect trends.

Scattered woody vegetation, as represented by the two variables transitional woodland-shrub and small woody features, was on top rankings among the predictors and greater proportions of these elements were accompanied by sharp increases of European brown hare density. Also warmer winter temperature had a positive effect.

We conclude that promoting scattered woody vegetation in agricultural landscapes is a powerful tool for improving European brown hare habitat quality. Particularly with the increasing dynamic in agriculture due to climate change, incentives and regulations that create a long-lasting heterogeneity in the landscape composition through near-natural elements can support the population of this popular mammal.