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Updated: Jul 5, 2026
08:43
Boldness, Aggression, and Shoaling Assays for Zebrafish Behavioral Syndromes
Published on: August 29, 2016
Quorum decision-making facilitates information transfer in fish shoals
Ashley J W Ward1, David J T Sumpter, Iain D Couzin
1Centre for Mathematical Biology, School of Biological Sciences, University of Sydney, Sydney, New South Wales 2006, Australia. ashleyjwward@gmail.com
Summary
Fish use "quorum responses," a threshold number of individuals signaling a behavior, to make collective decisions. This nonlinear response improves group decision-making accuracy and speed, especially under predation risk.
Area of Science:
- Animal behavior
- Collective intelligence
- Decision-making
Background:
- Understanding collective decision-making in vertebrate groups is limited.
- Animals may use others' behavior to inform their own decisions, especially when information sources are unclear.
Purpose of the Study:
- Investigate the role of quorum responses in collective movement decisions of fish.
- Determine if quorum responses enhance decision accuracy and reduce nonadaptive following behavior.
Main Methods:
- Experiments with three-spine sticklebacks (Gasterosteus aculeatus) in groups of varying sizes.
- Simulations to model decision-making accuracy and speed.
Main Results:
- Quorum responses explain stickleback collective movement decisions under predation risk.
- Larger groups (4-8 fish) ignored single conspecific signals, requiring multiple signals for influence.
- Quorum responses reduced nonadaptive following behavior.
Conclusions:
- Nonlinear responses, like quorum sensing, are crucial for effective information transfer in animal groups.
- Quorum responses improve group decision-making accuracy and speed compared to independent or linear responses.
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