Editor's Choice

J. L. Frair, E. H. Merrill, H. L. Beyer & J. M. Morales (2008) Thresholds in landscape connectivity and mortality risks in response to growing road networks. Journal of Applied Ecology, 45, 1504–1513. http://dx.doi.org/10.1111/j.1365-2664.2008.01526.x

Roads are an important factor structuring landscapes, and their ecological effects are often profound. The Journal of Applied Ecology has a long tradition of publishing studies that contribute to identifying the problems that accompany roads, including animal–vehicle collisions (Malo et al. 2004; Seiler 2005), corridors for invasive species (Jodoin et al. 2007) and landscape fragmentation (Kramer-Schadt et al. 2004). Our authors have also investigated the efficacy of management solutions to these issues, such as drainage culverts or crossings for small mammals (Clevenger et al. 2001; McDonald & Cassady St Clair 2004).

Our Editor's Choice this issue is an elegant paper that represents an important step forward in disentangling the interacting factors influencing elk behaviour at a local scale. Frair et al. (2008) showcases the strengths of an approach that combines strong empirical data, statistical and mechanistic modelling, and qualitative validation of model findings. They use a dataset of satellite-collared elk to derive a model of daily individual movement decisions, based on forage availability and road presence, building up simple models until the complexity is adequate to capture the key elements of observed behaviour. The results allow them to predict the non-linear effect of road density on elk presence, and importantly to separate out the effects of road density and the availability of preferred habitat on movement and hence distribution. Although the particular effect of roads on elk behaviour is specific to their study site, the modelling framework is usefully generalisable. It opens the possibility of scaling up from individual behaviour to landscape level distributions, and hence of exploring potential mitigation responses involving road design that takes the distribution of preferred habitat into account.

Our authors are developing an increasingly sophisticated understanding of the effects of human infrastructure on animal behaviour. However, the geographical bias of these studies is noticeable – they relate to Europe and North America. A similar study to Frair et al.'s that addresses the issue of managing to minimise the impact of road proliferation in a developing country would be most welcome.