Linking cognition with fitness in a wild primate: fitness correlates of problem-solving performance and spatial learning ability

Abstract

Linking the cognitive performance of wild animals with fitness consequences is crucial for understanding evolutionary processes that shape individual variation in cognition. However, the few studies that have examined these links revealed differing relationships between various cognitive performance measures and fitness proxies. To contribute additional comparative data to this body of research, we linked individual performance during repeated problem-solving and spatial learning ability in a maze with body condition and survival in wild grey mouse lemurs (Microcebus murinus). All four variables exhibited substantial inter-individual variation. Solving efficiency in the problem-solving task, but not spatial learning performance, predicted the magnitude of change in body condition after the harsh dry season, indicating that the ability to quickly apply a newly discovered motor technique might also facilitate exploitation of new, natural food resources. Survival was not linked with performance in both tasks, however, suggesting that mouse lemurs' survival might not depend on the cognitive performances addressed here. Our study is the first linking cognition with fitness proxies in a wild primate species, and our discussion highlights the importance and challenges of accounting for a species' life history and ecology in choosing meaningful cognitive and fitness variables for a study in the wild.This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.

Keywords: body condition; cognitive performance; fitness; primate; survival.

Figure 1.

Inter-individual variation in performance in two cognitive tests and two fitness proxies. Depicted are histograms of the two main cognitive measures, (a) solving time of the FE task and (b) number of errors made until the learning criterion in the maze, and the two fitness proxies, (c) BMI change and (d) days alive. (Online version in colour.)

Figure 2.

Relationship between BMI change and survival (number of days alive) and the cognitive performance measures, (a,c) solving time in the FE task and (b,d) number of errors in the maze. (a,b) BMI change: blue, males; grey, females; a positive BMI change corresponds to a decrease in BMI during the dry season, negative values reflect an increase in BMI from rainy to the end of dry season. (c,d) Survival: green, censored days alive for animals that are still alive; grey, dead animals. (Online version in colour.)