Individuals on the Landscape: Behavior Can Mitigate Landscape Differences among Habitats

We present a case study of the rose hip fly, Rhagoletis basiola, to demonstrate how one can connect landscape to population and evolutionary dynamics through the responses of individuals. Survey data from six different isolated rose habitats (Rosa sp.) near Vancouver, Canada were analyzed to determine the spatial distribution of rose hips within and among bushes. Rose hips were clumped at all sites; there was statistically significant variation in degree of clumping among sites. However, analyses using dynamic life history theory suggest that much of this variation may be mitigated by oviposition and movement response of individual flies to fruit distribution : sites that differ structurally may not differ evolutionarily. With this in mind, we provide five different indices that could be used to evaluate fly performance on different landscapes: I) the probability that a cell r units away contains resource, given that the current cell contains resource, 2) the probability that a cell r units away contains resource, given that the current cell is devoid of resource, 3) the optimal distance to move from a cell that harbors fruit, 4) the optimal distance to move from a cell that is devoid of fruit, and 5) the Expected Reproductive Success of a fly in a particular habitat. Those indices provide the link between landscape and individual behavior and suggest another way of addressing habitat conservation issues.