Flocks and Schools

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Flocks and Schools

 

(the Russian word staia conveys what in English is meant by a “flock” of birds and a “school” of fish), groups of birds and fishes, respectively, usually of the same species, that actively maintain contact with one another and coordinate their actions owing to temporarily shared biological conditions. Flocks of birds and schools of fish include individuals that perform several essential functions as members of the same group throughout most of their lives. Unlike the individuals of a herd, flocking birds and schooling fish do not recognize other group members, and there are no leaders or dominant and subordinate individuals. Flocks of birds and schools of fish consist of individuals of the same or different species and of different sexes and ages. Schooling fishes include herring, mackerel, and anchovies, and examples of flocking birds are geese, cranes, and sparrows. Birds generally do not form flocks at nesting times.

The biological significance of a flock or school depends on the condition of the animals and on environmental factors. Being in such a group helps in the search for food and prey, in defense against predators, in choosing a place to spend the night (birds), and in orientation and navigation during migration. The formation of a flock or school also seems to be important in improving hydrodynamic and aerodynamic conditions when moving in water or air, respectively. For example, the structure of a flock of birds in flight is in the form of a wedge (cranes), file (ducks), or loose mass (pigeons, sparrows). The size and shape of a flock or school, as well as the distance between individuals, are variable adaptations to different environmental conditions. The individuals in such a group signal to one another in different ways, mostly visually among fishes and visually and acoustically among birds. The patterns of group behavior among fishes are widely used in commercial fishing.

D. V. RADAKOV and V. E. IAKOBI

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.