Ecological correlates of dispersal distance in terrestrial mammals

Santini L., Di Marco M., Visconti P., Baisero D., Boitani L., Rondinini C. 2013. Ecological correlates of dispersal distance in terrestrial mammals. Hystrix 24(2): 1-6.

Abstract. Dispersal distance in mammals is a fundamental information for several ecological and conservation applications. Although dispersal can depend on many intrinsic and extrinsic factors, in recent years many studies have shown that it scales with body size and home range area. However, the role of further ecological correlates to distance travelled is still unclear and the predictive models proposed so far have suffered from small sample size and lack of error estimates. This reduces the practical relevance of the models for ecological and conservation applications. We conducted a comprehensive meta-analysis on 327 studies on the dispersal of 164 mammal species, and performed linear and non-linear regression analyses to explore the relationships of body size and home range area with dispersal distance. We tested the effect of various life history traits and ecological factors on the relationships and performed a sensitivity analysis to evaluate the robustness of the models to sample size. The linear relationships of both home range and body size with dispersal distance were influenced by various life history traits and ecological factors. We developed allometric functions to estimate species dispersal distance based on different predictors and life history traits. Linear models representing the relationship between dispersal distance and body size or home range area received good support; however logistic models better approximates both relationships. Despite receiving less support than a logistic curve, a linear model between dispersal and home range is a good approximation for applicative purposes. Sensitivity analysis showed that our results are robust to subsampling of the original dataset until a sample of 40 species. Our empirical models have the potential to improve theoretical and applied population biology studies by extending the applicability and improving the accuracy of dispersal distance estimation to a large number of mammals.

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