Dispersal of Drosophila melanogaster over landscapes with different food patch structures

Theoretical and empirical studies often show that within populations, individuals vary in their propensity to disperse. We aspired to understand how this behavioural variation is impacted by the distribution and pattern of food patches across a landscape. In a series of experiments, we examined how inter-patch distance and the distribution of food patches influenced dispersal in wild-type strains of Drosophila melanogaster with natural allelic variants of the foraging (for) gene known to influence dispersal in this species. The “rover” strain was homozygous for the forR allele (more dispersive) whereas the “sitter” strain was homozygous for fors (less dispersive). We also assessed an outbred population of flies with an unknown dispersal propensity. Dispersal was assayed in a multi-patch lab arena (25 cells, 5 x 5 array). In the inter-patch distance trials, landscapes of two different sizes (small vs. large) were used, both with food in all 25 cells. Dispersal was reduced in the large la...