title: Selfish-herd behaviour of sheep under threat.
abstract: Flocking is a striking example of collective behaviour that is found in insect swarms, fish schools and mammal herds. 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. 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. 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.
authors: Andrew J
authors: AJ
authors: King
authors: Alan M
authors: AM
authors: Wilson
authors: Simon D
authors: SD
authors: Wilshin
authors: John
authors: J
authors: Lowe
authors: Hamed
authors: H
authors: Haddadi
authors: Stephen
authors: S
authors: Hailes
authors: A Jennifer
authors: AJ
authors: Morton
mesh_terms: D000818:Animals; D004285:Dogs / Q000502:physiology*; D020387:Food Chain; D040362:Geographic Information Systems; D008954:Models, Biological; D009068:Movement; D011235:Predatory Behavior; D034561:Sheep, Domestic / Q000502:physiology*; D012919:Social Behavior; D013021:South Australia