title: Personality drives physiological adjustments and is not related to survival.
abstract: 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.
authors.affiliation: Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, , 1790 AB Den Burg, The Netherlands, Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, , PO Box 11103, 9700 CC Groningen, The Netherlands.
authors.forename: Allert I
authors.initials: AI
authors.lastname: Bijleveld
authors.forename: Georgina
authors.initials: G
authors.lastname: Massourakis
authors.forename: Annemarie
authors.initials: A
authors.lastname: van der Marel
authors.forename: Anne
authors.initials: A
authors.lastname: Dekinga
authors.forename: Bernard
authors.initials: B
authors.lastname: Spaans
authors.forename: Jan A
authors.initials: JA
authors.lastname: van Gils
authors.forename: Theunis
authors.initials: T
authors.lastname: Piersma
mesh_terms: D025041:Animal Migration; D000818:Animals; D046091:Charadriiformes / Q000033:anatomy & histology* / Q000502:physiology*; D005106:Exploratory Behavior; D005260:Female; D005895:Gizzard, Avian / Q000033:anatomy & histology*; D008136:Longevity; D008297:Male; D009426:Netherlands; D009929:Organ Size; D010551:Personality
keywords: behavioural syndrome; coping style; life-history trade-off; pace-of-life; phenotypic flexibility; temperament