Meeting Abstract
A primary determinant of long-term invasion success is a species’ ability to colonize novel environs. Colonization success is linked to the dispersal rates of individuals within the invading population. The traits that confer increased dispersal rates are often heritable and are, therefore, open to selection pressure. This pressure can lead to spatial sorting, whereby individuals that are more effective dispersers naturally align themselves along the invasion front, hastening the spread of the invasion. Using the extant invasion of Xenopus tropicalis in Florida as a system, we examined individual, sex, and site-level differences in both morphometry and performance as they relate to dispersal distance and success. We predicted that individuals that disperse should have longer hind-limbs and better stamina, relative to individuals that do not disperse. Additionally, we predicted that individuals with better exertion capacity would be more likely to disperse longer distances. We found significant differences in performance, with individuals that dispersed performing for longer intervals before reaching exhaustion than individuals that did not disperse. Additionally, we found that both morphometry and performance predicted dispersal distance, with dispersal distance increasing with both hind limb length and maximal exertion capacity. These results suggest that dispersal success is nonrandom with respect to morphometric and performance traits, and may indicate the real-time progression of spatial sorting.
