COS 103-2 - Exploring the links between cognition, provisioning and reproductive success in free living great tits (Parus major)

Background/Question/Methods

The ability to innovate (i.e. use novel or modified behaviours to solve a problem) has been found in many taxa and is thought to play a key role in rapid adaptation, accounting for the evolutionary success of some species. Recent studies showed that interindividual variations in problem-solving can be related to mating, reproductive success and survival in natural populations. Yet, whether and how variations in problem-solving are causally linked to fitness or whether a third variable is involved is currently unknown, which is a major knowledge gap in understanding how cognition can help animals to adapt to their changing environments. One largely assumed hypothesis suggest that individuals with better problem-solving abilities should be better able to find food for themselves and their chicks, enhancing their reproductive success and their own survival.

We tested this hypothesis in a wild great tit population (Parus major) where we collected breeding data (hatching date, brood size, number of fledglings). During chick rearing, we installed infrared cameras inside nest boxes to record food provisioning (feeding rate, size number and type of preys) and tested individual problem-solving ability (solver vs. non solvers) using a string-pulling task attached to the entrance of the nest box.

Results/Conclusions

We investigated whether problem-solving ability predicted food provisioning effort and how it related to reproductive success in 199 individuals from 114 breeding pairs. We expected that parents best able to solve the string-pulling task would supply their brood at a faster rate and with bigger and/or better preys. After taking into account known non-cognitive covariate of problem-solving performance (sex, age, neophobia), we first showed that although females were more likely to solve the task, solver males delivered preys at a higher rate and brought more larvae, a particularly nutritious prey, to their chicks, than non-solver males. Path analyses showed that both males and females solving status influenced their provisioning performances. However, we identified a causal link between problem solving status and reproductive success in males mediated by their foraging performance, whereas the underlying mechanism(s) remains to be discovered in females. Our study is the first to investigate in depth the link between problem-solving performance, provisioning and reproductive success, demonstrating adapting value of behavioural flexibility at the individual level.