Heritability of dispersal in the great reed warbler

Dispersal is commonly considered to be a condition-dependent behaviour with no or low heritability. Here, we show that dispersal in the great reed warbler (Acrocephalus arundinaceus ) has a high heritability. Analyses of capture-recapture data of male great reed warblers gathered from the species' whole Swedish breeding range revealed a remarkable offspring-parent resemblance in dispersal behaviour (philopatry vs. inter-population dispersal). Also, the degree of dispersal differed between cohorts, which shows that dispersal was partly conditionally dependent. The offspring to mid-parent estimate of heritability was 0.50. In a previous study of the same data set of male offspring, we did not detect associations between dispersal and several relevant environmental, parental and offspring condition factors. Thus, our results indicate that variation in dispersal partly has a genetic basis in great reed warblers.