Territory (animal)

For other uses, see Territory (disambiguation).

A male South China tiger scent-marking his territory

In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics (and, occasionally, animals of other species). Animals that defend territories in this way are referred to as territorial.

Classic territories

Northern Elephant Seals (Mirounga angustirostris) fighting for territory and mates.

Territorial animals defend areas that contain a nest, den or mating site, and sufficient food resources for themselves and their young. Defense rarely takes the form of overt fights: more usually there is a highly noticeable display, which may be visual (as in the red breast of the robin), auditory (as in much bird song, or the calls of gibbons) or olfactory, through the deposit of scent marks. Many territorial mammals use scent-marking to signal the boundaries of their territories; the marks may be deposited by urination, by defecation, or by rubbing parts of the bodies that bear specialised scent glands against the substrate. For example, dogs and other canids scent-mark by urination and defecation, while cats scent-mark by rubbing their faces and flanks against objects, as well as by the notoriously persistently smelly spraying of urine by tomcats. Many prosimians use territorial marking; for example, the Red-bellied Lemur creates territories for groups of two to ten individuals in the rainforests of eastern Madagascar by scent marking: the male Diademed Sifaka also scent marks defended territories in some of these same rainforests. Humans build physical impediments and visual warnings to mark defended territories. The male Western fence lizard defends a territory by posturing and combat, but less intensely after the mating season.

Invertebrates which show territoriality include some ants and bees, and the owl limpet.

Scent marking

See also: Spraying (animal behavior), Pheromones, and Spoor (animal)

Scent marking (also known as spraying or territorial marking) is behavior used by animals to identify their territory. Most commonly, this is accomplished by depositing strong-smelling substances, sometimes by urinating on prominent objects within the territory. Often the scent contains carrier proteins, such as the major urinary proteins, to stabilize the odours and maintain them for longer.

Not only does the marking communicate to others of the same species, but it is also noted by prey species and avoided. For example, felids such as leopards and jaguars mark by rubbing themselves against vegetation.^{[citation needed]} Prosimians and New World monkeys also use scent marking, including urine washing (self-anointing the body with urine), to communicate. Many ungulates, for example the Blue Wildebeest, use scent marking from two glands, the preorbital gland and a scent gland in the hoof.^{[citation needed]}

White-tailed deer

See also: Urine spraying#Cervidae

White-tailed deer possess many glands that allow them to produce scents, some of which are so potent they can be detected by the human nose. Four major glands are the pre-orbital, forehead, tarsal, and metatarsal glands. It was originally thought that secretions from the preorbital glands (in front of the eye) were rubbed on tree branches; recent research suggests this is not so. It has been found that scent from the forehead or sudoriferous glands (found on the head, between the antlers and eyes) is used to deposit scent on branches that overhang "scrapes" (areas scraped by the deer's front hooves prior to rub-urination). The tarsal glands are found on the upper inside of the hock (middle joint) on each hind leg. Scent is deposited from these glands when deer walk through and rub against vegetation. These scrapes are used by bucks as a sort of "sign-post" by which bucks know which other bucks are in the area, and to let does know that a buck is regularly passing through the area—for breeding purposes. The scent from the metatarsal glands, found on the outside of each hind leg, between the ankle and hooves, may be used as an alarm scent. The scent from the Interdigital glands, which are located in between the hooves of each foot, emit a yellow waxy substance with an offensive odor. Deer can be seen stomping their hooves if they sense danger through sight, sound, or smell, this action leaves an excessive amount of odor for the purpose of warning other deer of possible danger.

Throughout the year deer will rub-urinate, a process during which a deer squats while urinating so that urine will run down the insides of the deer's legs, over the tarsal glands, and onto the hair covering these glands. Bucks rub-urinate more frequently during the breeding season. Secretions from the tarsal gland mix with the urine and bacteria to produce a strong smelling odor. During the breeding season does release hormones and pheromones that tell bucks that a doe is in heat and able to breed. Bucks also rub trees and shrubs with their antlers and head during the breeding season, possibly transferring scent from the forehead glands to the tree, leaving a scent other deer can detect.

Sign-post marking (scrapes and rubs) are a very obvious way that white-tailed deer communicate. Although bucks do most of the marking, does visit these locations often. To make a rub, a buck will use its antlers to strip the bark off of small diameter trees, helping to mark his territory and polish his antlers. To mark areas they regularly pass through bucks will make scrapes. Often occurring in patterns known as scrape lines, scrapes are areas where a buck has used its front hooves to expose bare earth. They often rub-urinate into these scrapes, which are often found under twigs that have been marked with scent from the forehead glands.

Defense

Territories may be held by an individual, a mated pair, or a group. Territoriality is not a fixed property of a species: for example, robins defend territories as pairs during the breeding season and as individuals during the winter, while some nectarivores defend territories only during the mornings (when plants are richest in nectar). In species that do not form pair bonds, male and female territories are often independent, in the sense that males defend territories only against other males, and females only against other females; in this case, if the species is polygynous, one male territory will probably contain several female territories, while in some polyandrous species such as the Northern Jacana, this situation is reversed.

Quite often territories that only yield a single resource are defended. For example, European Blackbirds may defend feeding territories that are distant from their nest sites, and in some species that form leks, for example the Uganda kob (a grazing antelope), males defend the lek site (which is used only for mating).

Two territorial American Kestrels attacking a Red-tailed Hawk.

Territoriality is only shown by a minority of species. More commonly, an individual or a group of animals will have an area that it habitually uses but does not necessarily defend; this is called its home range. The home ranges of different groups often overlap, and in the overlap areas the groups will tend to avoid each other rather than seeking to 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 rather than defense.

Behavioural ecologists have argued that food distribution determines whether a species will be territorial or not. This however, though true as far as it goes, is too narrow a point of view. As mentioned above, there are several kinds of territoriality; for example, the defence of lek areas by kob has nothing to do with food. Many other examples of territorial defence, including fish, birds or even invertebrates, are related to competition for mates or safe lairs, rather than food. Territoriality will emerge where there is a focused resource that provides enough for the individual or group, within a boundary that is small enough to be defended without the expenditure of too much effort.

Many birds, particularly seabirds, though they nest in dense communities, are nonetheless territorial in that they defend their nesting site to within the distance that they can reach while brooding. This is necessary to prevent attacks on their own chicks or nesting material from neighbours. Commonly the resulting superimposition of the short-range repulsion onto the long-range attraction characteristically leads to the well-known roughly hexagonal spacing of nests. Interestingly, one gets a similar hexagonal spacing resulting from the territorial behaviour of gardening limpets such as species of Scutellastra They vigorously defend their gardens of particular species of algae, that extend for perhaps 1–2 cm around the periphery of their shells.

Territoriality is least likely with insectivorous birds, where the food supply is plentiful but unpredictably distributed. Swifts rarely defend an area larger than the nest. Conversely, other insectivorous birds that occupy more constrained territories, such as the ground-nesting Blacksmith Lapwing may be very territorial, especially in the breeding season, where they not only threaten or attack many kinds of intruders, but have stereotyped display behaviour to deter conspecifics sharing neighbouring nesting spots.

Conversely, large solitary (or paired) carnivores, such as bears and the bigger raptors require an extensive protected area to guarantee their food supply. This territoriality will only break down when there is a glut of food, for example when Grizzly Bears are attracted to migrating salmon.

Polyterritoriality

Many species demonstrate the behavior of polyterritoriality, referring to the act of claiming or defending more than one territory. In the European pied flycatcher (Ficedula hypoleuca), researchers assert that males exhibit polyterritoriality in order to deceive females of the species into entering into polygynous relationships. This hypothesis, named the deception hypothesis, claims that males have territories at far enough distances that females will not be able to discern already-mated males. The observation that males traveled long distances, ranging from 200m to 3.5km, to find a second mate seemed to be supportive of the argument. The debate about the polyterritoriality in this species may be able to spark research about the evolution of and reasons for polyterritoriality in other completely unrelated species.

See also

• Dominance (ethology)
• Aggression
• Alpha (biology)
• Biological interaction
• Dear enemy recognition

In specific species

• Canids
  • Gray wolf#Social and territorial behaviors
  • Red_fox#Social_and_territorial_behaviour
• Dhole#Social and territorial behaviours
• Felids
  • Tiger#Territorial behaviour
  • Cheetah#Territories
  • Cougar#Social structure and home range
  • Lion#Group organization
  • Jaguar#Social activity
  • Leopard#Social structure and home range
• Other
  • Black rhinoceros#Communication
  • Spotted hyena#Social behaviour
  • Pemphigus betae#Leaf colonization

Further reading

• Walther, F. R., E. C. Mungall, G. A. Grau. (1983) Gazelles and their relatives : a study in territorial behavior Park Ridge, N.J. : Noyes Publications 239, ISBN 0-8155-0928-6
• Stokes, A. W. (editor) (1974) Territory Stroudsburg, Pa., Dowden, Hutchinson & Ross 398, ISBN 0-87933-113-5
• Klopfer, P. H. (1969) Habitats and territories; a study of the use of space by animals New York, Basic Books 117 p.