Modelling roe deer (Capreolus capreolus) in a gradient of forest fragmentation: behavioural plasticity and choice of cover

Abstract

The ability of a species to exhibit behavioural plasticity to environmental conditions has consequences for its success in fragmented landscapes. The roe deer, Capreolus capreolus (L., 1758), is one of the foremost examples of behavioural flexibility among ungulates. This species has increased rapidly in range from its original forest-mosaic habitat into open agricultural plains. Open-land roe deer populations show distinct differences in spatial and social behaviour, including larger group sizes, compared with forest-living roe deer populations. This is traditionally viewed as an antipredator strategy. The presence of strong behavioural plasticity in species response to landscape structure suggests that this should also be a concern in models attempting to describe effects of landscape change on species distribution. To date the implications of behavioural plasticity for modelling species' response to environmental conditions has received little attention. We used an individual-based model of roe deer to evaluate the consequences of behavioural plasticity for predictions made regarding population response to woodland fragmentation. The inclusion of a flexible behavioural strategy, where increased group size could buffer lack of woodland cover, resulted in significantly higher estimates of population size, population persistence, and the ability of the population to cope with fragmentation. This clearly demonstrates that behavioural plasticity in species response to landscape structure may affect our ability to accurately predict the effects of landscape change and should be a concern to modellers.