Context-dependent group size choice in fish
Authored by Iain D Couzin, J Krause, DJ Hoare, JGJ Godin
Date Published: 2004
DOI: 10.1016/j.anbehav.2003.04.004
Sponsors:
National Science and Engineering Research Council of Canada (NSERC)
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
The costs and benefits of group membership vary with the size of groups, and individuals are expected to modify their choice of groups in
response to ecological factors such as food availability and predation
risk. We experimentally examined context-dependent group size choice in
a shoaling fish, the banded killifish, Fundulus diaphanus, by using
nondirectional odour cues to simulate a food source or a successful
attack by a predator (food or alarm treatments) in the laboratory. Group
sizes were significantly smaller in the food treatment and larger in the
alarm treatment than in control trials. When presented with food and
alarm cues together, fish formed groups that were larger than control
groups but smaller than those seen with alarm cues alone. These results
are consistent with theoretical predictions based on the known benefits
and costs of grouping and with previous laboratory work examining the
individual shoal choice behaviour of single fish. To examine possible
mechanisms of group formation, we developed an individual-based model of
shoaling behaviour in which simulated fish were allowed to modify the
area over which they interacted with neighbouring individuals. Group
size distributions produced by the model were a good approximation of
our experimental data. We suggest that local behavioural interaction
rules of this type are a potential mechanism by which fish may
individually adjust grouping behaviour without requiring extensive
information on the position and movement of all possible shoalmates. (C)
2004 The Association for the Study of Animal Behaviour. Published by
Elsevier Ltd. All rights reserved.
Tags
Trade-offs
Predator avoidance
Schooling behavior
Gasterosteus-aculeatus
Shoal size
Killifish fundulus-diaphanus
Banded
killifish
3-spined sticklebacks
Aggregation
behavior
Cyprinodontid fish