HERD EFFECTS
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(1) |
| ID | ◀ 1514 ▶ |
| Object type | General information, Human sciences, Methodology or model |
The protective effects for individuals resulting from congregation in considerable numbers.
Such effects can be observed in numerous different animal species: fish shoals , nesting birds, gregarious mammals, insects flights, etc…
Those individuals at the center of the herd are better protected because they are completely surrounded by individuals of the same species which are not dangerous to them. The peripherical individuals are more at risk because, on the outer ring, they are in direct contact with the space of possible predators. In most cases “insiders” and “outsiders” rotate, which is globally efficient for the whole flock.
Observing nesting birds, Diane BRUNTON (Yale University) discovered that the central area is at a disadvantage when the predator is airborne, thus able to make use of the third dimension . In that case, the central density of the flock offers increased opportunities to the predator.
(Source: The Economist, Oct. 18th 1997)
See also
Edge effect