Within-individual canalization contributes to age-related increases in trait repeatability: A longitudinal experiment in red knots

Eva M.A. Kok*, Joseph B. Burant, Anne Dekinga, Petra Manche, Darren Saintonge, Theunis Piersma, Kimberley J. Mathot

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

4 Citations (Scopus)
179 Downloads (Pure)

Abstract

Age-related increases in the repeatable expression of labile phenotypic traits are often assumed to arise from an increase in among-individual variance due to differences in developmental plasticity or by means of state-behavior feedbacks. However, age-related increases in repeatability could also arise from a decrease in within-individual variance as a result of stabilizing trait expression, that is, canalization. Here we describe age-related changes in within-individual and among-individual variance components in two correlated traits— gizzard mass and exploration behavior—in a medium-sized shorebird, the red knot (Calidris canutus). Increased repeatability of gizzard mass came about due to an increase in among-individual variance, unrelated to differences in developmental plasticity, together with decreases in within-individual variance consistent with canalization. We also found canalization of exploration but no age-related increase in overall repeatability, which suggests that showing predictable expression of exploration behavior may be advantageous from a very young age onward. Contrasts between juveniles and adults in the first year after their capture provide support for the idea that environmental conditions play a key role in generating among-individual variation in both gizzard mass and exploration behavior. Our study shows that stabilization of traits occurs under constant conditions: with increased exposure to predictable cues, individuals may become more certain in their assessment of the environment allowing traits to become canalized.

Original languageEnglish
Pages (from-to)455-469
Number of pages15
JournalAmerican Naturalist
Volume194
Issue number4
Early online date6-Aug-2019
DOIs
Publication statusPublished - Oct-2019

Keywords

  • Consistent among-individual differences
  • State-behavior feedbacks
  • Variance partitioning
  • Within-individual variation
  • STATE-BEHAVIOR FEEDBACKS
  • COST-BENEFIT-ANALYSIS
  • EXPLORATORY-BEHAVIOR
  • PERSONALITY-TRAITS
  • FORAGING BEHAVIOR
  • CALIDRIS-CANUTUS
  • BAYESIAN MODELS
  • LONG-TERM
  • ECOLOGY
  • CONSEQUENCES

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