Crop Phenology Reshapes the Food-Safety Landscape for Roe Deer in an Agroecosystem

Understanding the behavioural adjustments of wildlife in anthropized landscapes is key for promoting sustainable human-wildlife coexistence. Little is known, however, about how synanthropic species navigate spatio-temporal variation in the availability of food and cover that are shaped by human practices such as agriculture. Animal habitat use is predominantly driven by spatial and temporal variations in food and cover, as individuals respond to fluctuations in the trade-off between food acquisition and risk avoidance. In agroecosystems, the availability of high-quality forage and cover are dependent on agricultural practices (e.g., harvesting) and crop phenology, providing an ideal opportunity to evaluate how wildlife adjust their behaviour in a heterogeneous human-dominated landscape. We investigated the influence of crop phenology on the behaviour of European roe deer (Capreoluscapreolus) to infer the functional roles of crop types in the food-cover landscape. We analysed the habitat use and activity patterns of 105 GPS-collared female roe deer using a unique dataset combining field-specific land cover data, region-specific estimates of crop phenology and weekly harvesting data for three common crops in a French agroecosystem. We found very distinct habitat use and activity patterns according to crop type, phenological stage and time of day. Wheat and artificial meadows were strongly selected at night-time during the early and post-harvest stages only, when roe deer were highly active, suggestive of feeding activity. On the contrary, roe deer strongly selected maize during the day when it was high enough to provide cover,when they were less active, indicating that it was primarily used for refuge. These patterns depended on the availability of more ‘natural’ cover, suggesting that mature maize may substitute for ‘natural’ cover when the latter is scarce. Our work highlights the importance of behavioural plasticity and habitat complementation in the persistence of this synanthropic species in agroecosystems. This behavioural adjustment may buffer the consequences of the reduction in natural habitats that accompanies intensification of agricultural production and has implications for understanding how agricultural practices shape the food-safety trade-off of wildlife living in these highly modified landscapes.