Data from: Personality drives physiological adjustments and is not related to survival

The evolutionary function and maintenance of variation in animal personality is still under debate. Variation in the size of metabolic organs has recently been suggested to cause and maintain variation in personality. Here, we examine two main underlying notions: (i) that organ sizes vary consistently between individuals and cause consistent behavioural patterns, and (ii) that a more exploratory personality is associated with reduced survival. Exploratory behaviour of captive red knots (Calidris canutus, a migrant shorebird) was negatively rather than positively correlated with digestive organ (gizzard) mass, as well as with body mass. In an experiment, we reciprocally reduced and increased individual gizzard masses and found that exploration scores were unaffected. Whether or not these birds were resighted locally over the 19 months after release was negatively correlated with their exploration scores. Moreover, a long-term mark–recapture effort on free-living red knots with known gizzard masses at capture confirmed that local resighting probability (an inverse measure of exploratory behaviour) was correlated with gizzard mass without detrimental effects on survival. We conclude that personality drives physiological adjustments, rather than the other way around, and suggest that physiological adjustments mitigate the survival costs of exploratory behaviour. Our results show that we need to reconsider hypotheses explaining personality variation based on organ sizes and differential survival.Repeatability of exploratory behaviour in red knotsThis data file contains an individual's experimental exploration score, field gizzard mass, and body mass at each replicate as well as their sex. See the ReadMe file for more information.01_exploration_repeatability.csvExploration scores and manipulated gizzard massesThis file contains data on experimental exploration scores in relation to their manipulated gizzard masses. See the ReadMe file for more information.02_exploration_gizzard_manipulation.csvExploration scores and whether a bird was resighted after its releaseThis data file contains experimental exploration scores, gizzard masses, and whether these birds were resighted after their release into the wild. See the ReadMe file for more information.03_resightings_experimental_birds.csvEncounter histories of free living red knots and their gizzard masses at captureThis file contains data on encounter histories (1998-2013) of free-living red knots together with their recorded gizzard masses at capture. These data were used in the MARK capture-recapture analyses. See the ReadMe file for more information.04_encounterhistory_free_living_birds.cs