Early environmental conditions do not impact behavioural flexibility in an invasive and noninvasive lizard species

Behavioural flexibility, the ability to adjust behaviour adaptively in response to internal or external changes, is expected to be crucial for animals adapting to environmental fluctuations. However, conditions experienced during early development can profoundly impact behavioural flexibility, making it unclear how populations will respond to novel circumstances. Stressful situations faced by the parents can have a direct impact on offspring cognition through the transmission of glucocorticoids, stress-related hormones that affect offspring cognition. At the same time, stressful conditions can influence parental behaviours during nesting and, consequently, the thermal developmental conditions that offspring experience. Here, we investigated the interactive effects of prenatal corticosterone (CORT) levels and temperature on behavioural flexibility in two lizard species: Lampropholis delicata and Lampropholis guichenoti. We manipulated prenatal CORT levels and incubation temperature in a 2 × 2 factorial design and then assessed behavioural flexibility through a reversal learning task. We hypothesized that prenatal CORT levels and cold temperatures would impair performance in the reversal task. We expected L. delicata, given its success as an invasive species, to show more flexibility and be less susceptible to early environmental conditions. Contrary to our expectations, behavioural flexibility appears robust to prenatal temperatures and CORT levels in both species. The lack of difference in reversal learning between L. delicata and L. guichenoti suggests that novel environments are unlikely to influence flexible behavioural learning, and behavioural flexibility itself is unlikely to explain differences in invasion success between these species.