Flight capacity increases then declines from the core to the margins of an invasive species' range

Individuals that disperse farther than other individuals are more likely to be on the frontlines of spreading populations and may be more likely to mate with one another as a consequence of their spatial proximity. Over generations, this process—known as spatial sorting—can produce patterns of increasing dispersal ability from a population's core towards the spreading front. By contrast, when the spread of a population is limited by the availability of suitable habitat, theory predicts that range boundaries can select against more dispersive phenotypes and produce patterns of decreasing dispersal capacity towards population margins. In a common garden study of invasive kudzu bugs (Megacopta cribraria)—which are limited by the availability of hostplants in their southern and western margins—I show that midrange individuals fly 49% farther than individuals in the core and 37% farther than individuals at margins. This result highlights that other processes, such as maternal effects or selection at range boundaries, may create more complicated patterns of dispersal ability across landscapes than predicted by models of spatial sorting alone.Please see READ ME file for more information regarding the two datasets.These data are from a common garden study of kudzu bug flight performance, as measured on flight mills (see methods). Each row describes measurements from a single individual and includes characteristics associated with the site from which it was collected. There are two datasets: (1) a complete dataset with all flights, including individuals that did not fly, and (2) a reduced dataset, which excludes non-flying insects and those that flew two rotations or less