Genotypic variation in refractory periods and habitat selection by natal dispersers

Refractory periods at the onset of dispersal occur when individuals initially do not settle in response to cues from naturally occurring habitats. The current paper focuses on relationships between refractory periods and habitat selection behaviour when natal dispersers use sequential search tactics. We first show how individual differences in acceptance thresholds can produce predictable relationships across individuals between the duration of their refractory periods and the time when they become responsive to cues from less preferred habitats. We then test these predictions using recurrent F1 crosses (genotypes) of Drosophila melanogaster. We found consistent differences between genotypes with respect to the duration of their refractory periods, and strong correlations across the genotypes between the duration of refractory periods and the time when individuals accepted cues from less preferred habitats, the time when they accepted habitats with supernormal cues, and an estimate of the total time available for search. Taken together, these results support the hypothesis that individual differences in acceptance thresholds can lead to correlations across individuals between the duration of the refractory period and the time during search when they accept less preferred habitats. We discuss the implications of these results for studies of habitat selection by natal dispersers, and for studies of individual differences in other behavioural contexts (i.e. mate choice) in which animals search for a single item with a large impact on fitness.