Boldness and intermittent locomotion in the bluegill sunfish, Lepomis macrochirus

Abstract

Intermittent locomotion, characterized by moves interspersed with pauses, is a common pattern of locomotion in animals, but its ecological and evolutionary significance relative to continuous locomotion remains poorly understood. Although many studies have examined individual differences in both intermittent locomotion and boldness separately, to our knowledge, no study to date has investigated the relationship between these 2 traits. Characterizing and understanding this relationship is important, as both locomotion and boldness are associated with several ecologically relevant behaviors such as foraging, mating, predator evasion, exploration, and dispersal. Here, we report on individual differences in boldness (risk-taking behavior) and intermittent locomotion in a novel laboratory environment in field-caught juvenile bluegill sunfish (Lepomis macrochirus). Our results show that juvenile bluegill sunfish exhibited individual-level variation in 2 modes of intermittent locomotion (undulatory and labriform swimming) and that this variation was correlated with differences in their boldness behavior. Generally, bolder individuals spent more time moving fast for longer durations and with shorter pauses than more timid individuals. Neither boldness nor locomotion was correlated with body size or body condition. This study provides the first empirical evidence for a link between an animal "personality" trait and intermittent locomotion.