Selfish-herd behaviour of sheep under threat
Flocking is a striking example of collective behaviour that is found in insect swarms, fish schools and mammal herds [1]. A major factor in the evolution of flocking behaviour is thought to be predation, whereby larger and/or more cohesive groups are better at detecting predators (as, for example, i...
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Published in | Current biology Vol. 22; no. 14; pp. R561 - R562 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Elsevier Inc
24.07.2012
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Subjects | |
Online Access | Get full text |
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Summary: | Flocking is a striking example of collective behaviour that is found in insect swarms, fish schools and mammal herds [1]. A major factor in the evolution of flocking behaviour is thought to be predation, whereby larger and/or more cohesive groups are better at detecting predators (as, for example, in the ‘many eyes theory’), and diluting the effects of predators (as in the ‘selfish-herd theory’) than are individuals in smaller and/or dispersed groups [2]. The former theory assumes that information (passively or actively transferred) can be disseminated more effectively in larger/cohesive groups, while the latter assumes that there are spatial benefits to individuals in a large group, since individuals can alter their spatial position relative to their group-mates and any potential predator, thus reducing their predation risk [3]. We used global positioning system (GPS) data to characterise the response of a group of ‘prey’ animals (a flock of sheep) to an approaching ‘predator’ (a herding dog). Analyses of relative sheep movement trajectories showed that sheep exhibit a strong attraction towards the centre of the flock under threat, a pattern that we could re-create using a simple model. These results support the long-standing assertion that individuals can respond to potential danger by moving towards the centre of a fleeing group [2]. |
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Bibliography: | http://dx.doi.org/10.1016/j.cub.2012.05.008 SourceType-Other Sources-1 ObjectType-Article-2 content type line 63 ObjectType-Correspondence-1 |
ISSN: | 0960-9822 1879-0445 |
DOI: | 10.1016/j.cub.2012.05.008 |