The effects of woodland fragmentation and human activity on roe deer distribution in agricultural landscapes

Abstract

Landscape structure and human activity influence the distribution and abundance of species. Landscape modifications have resulted in loss of habitat, increased isolation between remnant patches, and increased disturbance. We compare distributions and group sizes of roe deer across four open agricultural landscapes of differing structure. The roe deer, essentially a woodland species, exhibits behavioural plasticity, recently colonising the agricultural plain. Our results suggest that the switch between forest and field behaviour may involve a threshold of landscape geometry concerning woodland connectivity. Where woodland fragments are numerous and widely dispersed, roe deer retain strong links to woodland structures, probably for cover and social reasons. Where remaining woodland is clumped, with little edge, roe deer adopt an open field habit, remaining at a distance from woodland. Average winter group size increased with distance from woodland, resulting in large herds typical of field roe deer populations at the more open sites. In addition, roe deer avoided areas associated with human activity, probably because of associated disturbance, particularly where woodland cover was lacking. Finally, average group size was lower in areas where the level of human activity was high. The behavioural plasticity of this species means that landscape change may not be limiting. Therefore, to predict the effects of landscape modification, models need to incorporate variation in the animal–landscape relationship due to behavioural plasticity.