Effects of habitat loss on populations of white-footed mice: testing matrix model predictions with landscape-scale perturbation experiments

Abstract

Habitat loss is the leading cause of decline in wildlife diversity and abundance throughout the world, but its effects on wildlife are not always predictable. Matrix population modeling is an increasingly common tool used to predict the effects of habitat loss. In spite of the growing number of studies using this approach, and its wide use in conservation practice, the predictions generated by matrix population models are rarely explicitly tested in the field. We compared the ability of a suite of spatially explicit demographic matrix models to predict the response of white-footed mice to loss of high quality habitat at mosaic sites in northeast Connecticut, USA. We tested short-term model predictions with landscape scale habitat perturbation experiments, including clear-cut logging or prescribed burning of high quality habitat at two study sites. Comparison of each model’s predictions with the observed responses at both sites qualitatively supported predictions that perturbation of high quality habitat would have negative effects extending into the surrounding landscape. The best-supported model assumed that evicted residents of the perturbed habitat would successfully resettle in nearby intact habitats, and allowed for gradual population recovery in the perturbed habitat. Similarly, long-term simulations (20 years) revealed how loss of a single habitat could trigger population declines throughout a mosaic site. This study shows that careful consideration of model assumptions such as those pertaining to resettlement behavior is crucial if predictions are to be reliable, and highlights the role of experiments for comparing alternative model predictions.