Here is the abstract:
To reduce the impact of biological invasions, we need to understand the behavioural mechanisms that enable some species to be successful invaders. Testing differences in behaviour between sympatric congeneric species with different invasive potential is an opportunity to study specific behavioural traits associated with invasion success. Using the invasive Italian wall lizard, Podarcis sicula, and a noninvasive congeneric, the green Iberian wall lizard, Podarcis virescens, which live in sympatry in a location that is novel for P. sicula, we tested their exploratory behaviour, neophobia and boldness: all traits that should promote invasion success. The invasive P. sicula was more exploratory, bold and neophilic than the sympatric native P. virescens. Native lizards had highly repeatable behaviour, whereas in P. sicula boldness was the only behavioural trait that was repeatable. The behavioural traits of the native species, but not the invasive species, were correlated. A lack of correlation between behavioural traits, as well as a lack of repeatability in two of the three behavioural traits, suggests higher levels of behavioural plasticity in P. sicula, which may also explain the success of this lizard during invasions. Our experiment highlights the potential importance of behavioural traits in invasions and provides insight into why P. sicula is such a successful invader.