Individual differences in activity and responses to a predator attack in juvenile smallmouth bass (Micropterus dolomieui)

by Smith, Kelly Lynne.

Jeffrey Miner Daniel Wiegmann The correlation of individual behaviour in different environmental contexts, known as a behavioural syndrome, constrains the optimization of behaviour within each context and recent studies reveal that the strength of behavioural syndromes differs across populations and over individual ontogeny. In this study, exploratory behaviour in an unfamiliar environment and behavioural responses to a simulated predator attack in the presence of a food source were measured in juvenile smallmouth bass (Micropterus dolomieui) collected from an isolated population. The results of this study revealed a behavioural syndrome: individuals who actively explored the unfamiliar environment also behaved more boldly in the presence of a predator. This behavioural syndrome suggests that there is a tradeoff between active exploratory behaviour, which may increase encounter rates with valuable resources and provide knowledge about the environment, and boldness in predator avoidance behaviour, which could result in increased exposure to predators. The population from which subjects were collected for this study has an unusually high abundance of smallmouth bass and the main predators at the juvenile life stage in the population are conspecific adults and larger juveniles. Previous studies have shown that fishes from systems with a diverse predation regime are more likely to exhibit behavioral correlations across contexts than populations that experience a less diverse predation regime, but this study suggests that predator density may also be an important factor in inducing behavioural correlations across contexts. iii