Animal personalities describe the behavioral phenotypes of individuals that often remain relatively stable over time and contexts. Since they can account for differential dispersal tendencies or impacts to native communities, understanding how personality types are distributed across the range of an invasive population can lead to important characterization of expanding populations. Cyrtophora citricola (Araneae: Araneidae) is a colonial tentweb orbweaver with a broad Old World native range that is invasive in Florida and increasingly abundant in the Western Hemisphere. In this study, we compare the spatial structure and composition of individual personality types in two invasive populations from Florida with two native populations from Spain and South Africa. Field and laboratory assays of behavioral traits such as boldness, exploratory tendency, activity, and foraging aggression were used to quantify the personality types compared across different spatial levels within a population (colony, site, and range-level).
Results/Conclusions
In the invasive Florida range, personality types were spatially assorted at the range level for some of the assayed behavioral traits. Spiders at the northern leading edge were bolder and there was higher variation in exploratory tendency compared to the population core. No differences were found in general activity levels and their latency to attack prey. This is consistent with the spatial sorting hypothesis, in which dispersal or reproduction-related phenotypes accumulate at expanding range fronts of dynamic populations. In their native range, patterns were less apparent at the range level. Instead, personality type composition was best predicted at the site level, which is predicted for more established populations being shaped by site-specific selective pressures.