Guðbjörg Ásta Ólafsdóttir

Research on among individual variation in behavior has increased rapidly in recent years. It is intuitively appealing that variation in the behavior of individuals has ecological consequences, for example, on trophic niche. Bold individuals, with a tendency to be explorative and risk‐tolerant, can be less likely to alter their foraging behavior based on context and, therefore, forage more consistently. Stable isotopes are a useful tool to retrospectively estimate ecological niche and have been found to correlate with foraging behavior in the wild and can be used to extend studies to further examine the ecological or evolutionary relevance of animal personality measured in the laboratory. We examined if common behavioral traits related to ecological niche in the wild using a rapid behavioral assay and δ 13 C and δ 15 N stable isotopes from fin and muscle, reflecting ecological niche for the previous weeks and months. We found that bolder stickleback (and females) were enriched in δ 13 C compared with shyer stickleback (and males) but the covariation of gender and stable isotope values complicate inferences. Nevertheless, the current results highlight the long‐term ecological importance of among individual variation in behavior and are among the first to support a correlation between laboratory measures of behavior and ecological niche in the wild and to document gender differences in stable isotope values of fish.