Developmental temperature has sex-specific effects on behavioural plasticity

As climate change progresses, species persistence will be influenced by the ability to adjust behaviour in response to rising temperatures. Thermal environments experienced in early development can have permanent effects on phenotype. However, it is largely unexplored whether these effects subsequently impact behavioural plasticity in response to thermal environments experienced after this early developmental period. To address this, we incubated delicate skink eggs (Lampropholis delicata) across three temperature treatments and quantified activity, microhabitat choice, and dispersal in mild and hot environments when skinks reached four to six weeks of age. Effects of incubation and thermal environment, as well as their interaction, were sex- and behaviour-specific. Differences in incubation temperature affected behavioural variation in response to thermal environment most strongly for activity, followed by dispersal, with no effect on microhabitat use. Males were the most plastic sex. Hot-incubated males had the greatest increase in activity and cool-incubated males dispersed further in a hot environment. Mild-incubated males were also the most dispersive compared to other male incubation groups. In contrast, females did not differ as often between incubation treatments or thermal environments. These results highlight sex-dependent effects of developmental temperature on behavioural plasticity, indicating climate change may impact males and females differently. If these effects result in sex-specific effects on survival, there may be implications for population growth and dynamics with a changing climate.