Predators around: should I stay or should I go? Mum knows it. Role of maternal effect in an adaptive dispersal decision.
Final Report Abstract
Predation is a fundamental ecological factor influencing many traits of prey species, most notably their behavior. Other than directly reacting to a predation treath, preys also induce behavioral changes in their offspring by means of maternal effects. In order to be adaptive, such modifications should allow females to tune their offspring's behaviour to the local predation risk. The project investigated predator-dependent maternal effects in the common lizard, Zootoca vivipara. Main objectives were: i) to test if pregnant females were able to use an environmental cue, i.e. the local predation risk, in order to manipulate their offspring behaviour and, ii) to investigate the potential adaptive value of such predator-dependent maternal effects. We observed different behavioral responses comparing gravid females exposed to the smell of a saurophagous snake and their offspring. While exposed females walked less in a novel environment than controls (lower activity), their offspring took more time in entering such novel environment (higher neophobia) but walk more once entered (higher activity), than offspring from control mothers. Therefore, direct and maternally-mediated antipredator responses showed peculiar characteristics. Our findings support the adaptive nature of predator-dependent maternal effects, because the offspring, by means of higher caution and higher tendency to disperse from a risky natal environment, are likely to decrease predation risk. Overall, the project's results show that gravid female common lizards, under risk of predation, adjust their behavior and are able to modify the behavior of their offspring adaptatively. The project has therefore answered the two main research questions considered, providing evidence that females of Zootoca vivipara are able to influence their offspring's behaviour at birth via transgenerational effects that likely increase their survival in a predator-rich environment.
