Can the assumption of a non‐random search improve our prediction of butterfly fluxes between resource patches?

Abstract

Abstract. 1. Understanding dispersal patterns that enable small, spatially isolated populations to survive in fragmented landscapes has become an important issue in conservation biology and landscape management. However, for most of the species of interest it is not known whether dispersing individuals navigate or follow systematic search strategies, as opposed to moving randomly.2. Recently it was shown that individuals of the butterfly species Maniola jurtina do not seek resources by means of random flight. If true, this may be problematic for existing metapopulation models, including those based on the evolution of dispersal rates in metapopulations.3. The study tested to what extent the non‐random dispersal patterns described in the literature can explain M. jurtina fluxes in its natural habitat.4. A model based on literature assumptions of M. jurtina movements is presented in the work reported here, and its predictions are compared with 2 years of capture–recapture data on its fluxes in two landscapes.5. The model provides a good fit to the data and gives better predictions than the model based only on patch sizes and distances between patches.6. Thus, if data are available about the actual landscape under consideration, the model should be preferred to simpler approaches; however, in general theoretical considerations the simple approach based on patch size and the degree of its isolation will retain its value.