Concept
In ethology, territory is the sociographical area that an animal consistently defends against conspecific competition (or, occasionally, against animals of other species) using agonistic behaviors or (less commonly) real physical aggression. Animals that actively defend territories in this way are referred to as being territorial or displaying territorialism. Territoriality is only shown by a minority of species. More commonly, an individual or a group of animals occupies an area that it habitually uses but does not necessarily defend; this is called its home range. The home ranges of different groups of animals often overlap, and in these overlap areas the groups tend to avoid each other rather than seeking to confront and expel each other. Within the home range there may be a core area that no other individual group uses, but, again, this is as a result of avoidance. The ultimate function of animals inhabiting and defending a territory is to increase the individual fitness or inclusive fitness of the animals expressing the behaviour. Fitness in this biological sense relates to the ability of an animal to survive and raise young. The proximate functions of territory defense vary. For some animals, the reason for such protective behaviour is to acquire and protect food sources, nesting sites, mating areas, or to attract a mate. Among birds, territories have been classified as six types. Type A: An 'all-purpose territory' in which all activities occur, e.g. courtship, mating, nesting and foraging Type B: A mating and nesting territory, not including most of the area used for foraging. Type C: A nesting territory which includes the nest plus a small area around it. Common in colonial waterbirds. Type D: A pairing and mating territory. The type of territory defended by males in lekking species. Type E: Roosting territory. Type F: Winter territory which typically includes foraging areas and roost sites. May be equivalent (in terms of location) to the Type A territory, or for a migratory species, may be on the wintering grounds.
