Do Behavioral Syndromes Affect Foraging Strategy and Risk-Taking in a Juvenile Fish Predator?

Abstract

Behavioral syndromes often have individuals varying along a continuum of personality traits. Some individuals exhibit bold or aggressive behaviors and are willing to explore novel stimuli, whereas others are shy and tend to avoid novel stimuli. Species that undergo an ontogenetic diet shift may experience a particularly important benefit if the shift to more-profitable prey is linked to this willingness to explore novel stimuli. However, actively selecting more-evasive prey can make these predators more vulnerable to predation themselves. We used largemouth bass Micropterus salmoides as a model to examine the role of behavioral syndromes in structuring predator strategies for dealing with these conflicting environmental pressures. Exploration behavior was first determined by testing willingness to explore a novel environment. Behaviors were then measured in two other contexts where exploration and boldness could potentially have fitness consequences: (1) the likelihood of consuming a novel prey item and (2) movement in the presence of a predator. Fish that tended to be exploratory consumed more total prey biomass than did fish that avoided a novel environment; however, the nonexploratory fish were more discriminating and targeted novel fish prey to a greater extent than did bold fish. Activity in the presence of a predator was not related to any other factor measured. Although our results provide no evidence that behavioral syndromes influence the predator avoidance behavior of largemouth bass, these syndromes do appear to play an important role in prey selection. Our study indicates that although behavioral syndromes do not necessarily affect behavior across all environmental contexts, they may influence feeding strategies and thus could potentially affect the timing of dietary shifts.

Received September 28, 2010; accepted May 23, 2011

ACKNOWLEDGMENTS

We thank J. Godbout, L. Freeman, R. Oplinger, L. Einfalt, and D. Ryan for their help with experiments and in the collection of fish. Additional support was provided by the Illinois Natural History Survey. All procedures conformed to the standards of the Institutional Animal Care and Use Committee at the University of Illinois.