Corticosterone responses differ between lines of great tits (Parus major) selected for divergent personalities.
Animal 'personality' describes consistent individual differences in suites of behaviors, a phenomenon exhibited in diverse animal taxa and shown to be under natural and sexual selection. It has been suggested that variation in personality reflects underlying physiological variation; however there is limited empirical evidence to test this hypothesis in wild animals. The hypothalamic-pituitary-adrenal axis is hypothesized to play a central role in personality variation. Here we tested whether in great tits Parus major variation in personality traits is related to plasma concentrations of corticosterone (CORT). Using a capture-restraint protocol we examined baseline and stress-induced CORT levels in two captive experimental groups: (1) birds selected for divergent personalities ('fast-bold' and 'slow-shy' explorers); and (2) non-selected offspring of wild parents. We first tested for differences in CORT between selection lines, and second examined the relationship between responses in a canonical personality test and CORT concentrations in non-selected birds. We found support for our prediction that the slow-shy line would exhibit a higher acute stress response than the fast-bold line, indicating a genetic correlation between exploratory behavior and stress physiology. We did not, however, find that continuous variation in exploratory behavior co-varies with CORT concentrations in non-selected birds. While our results provide support for the idea that personality emerges as a result of correlated selection on behavior and underlying physiological mechanisms, they also indicate that this link may be particularly evident when composite personality traits are the target of selection.
Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Schlossallee 2, 78315 Radolfzell, Germany. alex.baugh@gmail.com
Alexander T
AT
Baugh
Sonja V
SV
Schaper
Michaela
M
Hau
John F
JF
Cockrem
Piet
P
de Goede
Kees
K
van Oers
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D003345:Corticosterone / Q000097:blood*; D005106:Exploratory Behavior / Q000502:physiology; D005260:Female; D008297:Male; D046109:Passeriformes / Q000145:classification* / Q000502:physiology*; D010641:Phenotype; D013312:Stress, Physiological / Q000502:physiology
D003345:Corticosterone