From the Cover: Quorum decision-making facilitates information transfer in fish shoals

@article{ward08, abstract = {Despite the growing interest in collective phenomena such as "swarm intelligence" and "wisdom of the crowds," little is known about the mechanisms underlying decision-making in vertebrate animal groups. How do animals use the behavior of others to make more accurate decisions, especially when it is not possible to identify which individuals possess pertinent information? One plausible answer is that individuals respond only when they see a threshold number of individuals perform a particular behavior. Here, we investigate the role of such "quorum responses" in the movement decisions of fish (three-spine stickleback, Gasterosteus aculeatus). We show that a quorum response to conspecifics can explain how sticklebacks make collective movement decisions, both in the absence and presence of a potential predation risk. Importantly our experimental work shows that a quorum response can reduce the likelihood of amplification of nonadaptive following behavior. Whereas the traveling direction of solitary fish was strongly influenced by a single replica conspecific, the replica was largely ignored by larger groups of four or eight sticklebacks under risk, and the addition of a second replica was required to exert influence on the movement decisions of such groups. Model simulations further predict that quorum responses by fish improve the accuracy and speed of their decision-making over that of independent decision-makers or those using a weak linear response. This study shows that effective and accurate information transfer in groups may be gained only through nonlinear responses of group members to each other, thus highlighting the importance of quorum decision-making. 10.1073/pnas.0710344105}, author = {Ward, Ashley J. and Sumpter, David J. and Couzin, Iain D. and Hart, Paul J. and Krause, Jens }, citeulike-article-id = {2798764}, doi = {10.1073/pnas.0710344105}, journal = {Proceedings of the National Academy of Sciences}, keywords = {collective\_behavior, ecology, information\_diffusion}, month = {May}, number = {19}, pages = {6948--6953}, posted-at = {2008-05-16 18:46:02}, priority = {2}, title = {From the Cover: Quorum decision-making facilitates information transfer in fish shoals}, url = {http://dx.doi.org/10.1073/pnas.0710344105}, volume = {105}, year = {2008} }

TY - JOUR ID - ward08 L3 - citeulike-article-id:2798764 TI - From the Cover: Quorum decision-making facilitates information transfer in fish shoals JF - Proceedings of the National Academy of Sciences VL - 105 IS - 19 SP - 6948 EP - 6953 N2 - Despite the growing interest in collective phenomena such as "swarm intelligence" and "wisdom of the crowds," little is known about the mechanisms underlying decision-making in vertebrate animal groups. How do animals use the behavior of others to make more accurate decisions, especially when it is not possible to identify which individuals possess pertinent information? One plausible answer is that individuals respond only when they see a threshold number of individuals perform a particular behavior. Here, we investigate the role of such "quorum responses" in the movement decisions of fish (three-spine stickleback, Gasterosteus aculeatus). We show that a quorum response to conspecifics can explain how sticklebacks make collective movement decisions, both in the absence and presence of a potential predation risk. Importantly our experimental work shows that a quorum response can reduce the likelihood of amplification of nonadaptive following behavior. Whereas the traveling direction of solitary fish was strongly influenced by a single replica conspecific, the replica was largely ignored by larger groups of four or eight sticklebacks under risk, and the addition of a second replica was required to exert influence on the movement decisions of such groups. Model simulations further predict that quorum responses by fish improve the accuracy and speed of their decision-making over that of independent decision-makers or those using a weak linear response. This study shows that effective and accurate information transfer in groups may be gained only through nonlinear responses of group members to each other, thus highlighting the importance of quorum decision-making. 10.1073/pnas.0710344105 KW - collective_behavior KW - ecology KW - information_diffusion AU - Ward, Ashley AU - Sumpter, David AU - Couzin, Iain AU - Hart, Paul AU - Krause, Jens PY - 2008/05/13/ UR - http://dx.doi.org/10.1073/pnas.0710344105 ER -