'Selfish herds' of guppies follow complex movement rules, but not when information is limited

Kimbell, Helen S.; Morrell, Lesley J.

Abstract

Under the threat of predation, animals can decrease their level of risk by moving towards other individuals to form compact groups. A significant body of theoretical work has proposed multiple movement rules, varying in complexity, which might underlie this process of aggregation. However, if and how animals use these rules to form compact groups is still not well under- stood, and how environmental factors affect the use of these rules even less so. Here, we evaluate the success of different movement rules, by comparing their predictions with the movement seen when shoals of guppies ( Poecilia reticulata ) form under the threat of predation. We repeated the experiment in a turbid environment to assess how the use of the movement rules changed when visual information is reduced. During a simulated predator attack, guppies in clear water used complex rules that took multiple neighbours into account, forming compact groups. In turbid water, the difference between all rule predictions and fish movement paths increased, particularly for complex rules, and the resulting shoals were more fragmented than in clear water. We conclude that guppies are able to use complex rules to form dense aggregations, but that environmental factors can limit their ability to do so.

Citation

Kimbell, H. S., & Morrell, L. J. (2015). 'Selfish herds' of guppies follow complex movement rules, but not when information is limited. Proceedings of the Royal Society B: Biological Sciences, 282(1816), 1-7. https://doi.org/10.1098/rspb.2015.1558

• Journal Article Type: Article
• Acceptance Date: Sep 1, 2015
• Online Publication Date: Sep 23, 2015
• Publication Date: Oct 7, 2015
• Deposit Date: Oct 15, 2015
• Publicly Available Date: Nov 23, 2017
• Journal: Proceedings of the Royal Society. B, Biological sciences
• Print ISSN: 0962-8452
• Electronic ISSN: 1471-2954
• Publisher: The Royal Society
• Peer Reviewed: Peer Reviewed
• Volume: 282
• Issue: 1816
• Article Number: ARTN 20151558
• Pages: 1-7
• DOI: https://doi.org/10.1098/rspb.2015.1558
• Keywords: Selfish herds, Aggregation, Poecilia reticulata, Group living, Turbidity, Social behaviour
• Public URL: https://hull-repository.worktribe.com/output/379787
• Publisher URL: http://rspb.royalsocietypublishing.org/content/282/1816/20151558
• Additional Information: Authors' accepted manuscript of article published in: Proceedings of the Royal Society. B, Biological sciences, 2015, v.282, issue 1817