Consistent among-individual differences are found in most areas of biological research, and appear to constrain animals’ plasticity and thus the possibility to adapt optimally to the environment. Individual strategies to acquire, process, store and use information to solve cognitive tasks are likely to affect speed and flexibility of learning, and ecologically relevant decisions regarding foraging and predation risk. Theory suggests a functional link between individual variation in cognitive strategies and behaviour (animal personality) via speed-accuracy and risk-reward trade-offs.
To investigate the relationship between animal personality and cognition, and their implications for fitness, I measured individual differences in associative learning speed and flexibility, quantified via reversal learning, of bank voles (Myodes glareolus) along with their activity and boldness. I found that bolder and more active individuals were fast, inflexible and persistent in the associative learning tasks, whereas shyer and less active individuals were slow and flexible. I also found evidence for a speed-accuracy trade-off: correct choices in the cognitive tasks required more time for all individuals compared to incorrect choices, but bolder, more active voles always made their decisions faster than reactive ones.
I then exposed individuals with different profiles to outdoor enclosures with different risk levels at two food patches. While all animals responded to risk, fast individuals increasingly exploited both food patches, gaining access to more food and spending less time searching and exercising vigilance. Slow animals progressively avoided high-risk areas, concentrating foraging effort in the low-risk one, and devoting most of their time to vigilance.
These results confirm the hypothesis that individual differences in behaviour are reflected in different cognitive strategies, differentially trading off speed for flexibility and accuracy in cognitive tasks as well as in foraging and anti-predator decisions that underlie the individual risk-reward bias.
Collaborators: J.A. Eccard (UniPotsdam), M. Dammhahn (UniPotsdam, Germany), J. Jacob (Julius Kühn Institute, Münster, Germany), M. Zaccaroni (UniFirenze, Italy)