Maider Iglesias Carrasco, Jiayu Zhang, Daniel W.A. Noble

Exposure to increased temperatures during early development can lead to phenotypic plasticity in morphology, physiology, and behaviour across a range of ectothermic animals. In addition, maternal effects are known to be important contributors to phenotypic variation in offspring. Whether the two factors interact to shape offspring morphology and behaviour has been barely explored. This is critical since both incubation temperature and maternal resource investment are likely to change as consequence of altered environmental conditions. Using a fully-factorial design we explored how the manipulation of early thermal environment and yolk-quantity in eggs affected the morphology, performance and antipredator behaviour of two sympatric Australian species (Lampropholis delicata and L. guichenoti) that differ in a range of life-history traits. We found that juveniles from the hot treatment were larger than those on the cold treatment in L. guichenoti but not L. delicata. We also found that incubation temperature and maternal investment interacted to shape performance, measured as running speed. Finally, we found that maternal investment impacted antipredator behaviour, with animals from the yolk-reduced treatment incubated under cold conditions resuming activity faster after a simulated predatory attack in L. delicata, but not L. guichenoti. Our results highlight the importance of exploring the multifaceted role that environments play across generations to understand how different anthropogenic factors will impact wildlife in the future. In addition, our study shows that the responses to different anthropogenic factors can be species-specific.