Invasive species are common around the world, but we still do not know which traits are most important for successfully establishing in new environments. Different stages of the invasion process, including transport, introduction, establishment, and spread, can act as selective filters for different combinations of phenotypic traits. Theoretical and empirical studies predict that invasive populations should have suites of behaviours that improve dispersal and spread, including higher boldness, dispersal propensity, and activity levels than native populations. In this study, we tested these predictions by comparing the morphology, life history, and behaviour of an invasive populations of redback spiders, Latrodectus hasselti, from Japan to a population of native spiders from Australia, with additional comparisons of another invasive population from New Zealand. We found that both a longer-established invasive New Zealand population and the more recently-established invasive Japanese population were more dispersive than the native Australian population. The Japanese invasive population showed elevated levels of sibling cannibalism relative to the native population, which may increase total reproductive success of females under food limitation. Japanese spiders were also less bold in response to a simulated predator threat compared to the native Australian population. In contrast to the prediction that invasive populations would show uniformly fast life history traits, the invasive Japanese population was more fecund, yet took longer to develop than the native population under laboratory conditions. Overall, our results show that invasive populations are phenotypically distinct from native populations, with some behavioural, life history, and morphological traits that would increase spread (dispersal tendency, high fecundity) and persistence (sibling cannibalism) in new habitats.

We collected the data at the University of Toronto Scarborough in laboratory conditions. These are the raw data and haven't been processed.