Display (zoology)

Many male birds have brightly coloured plumage for display. This feather is from a male Indian peafowl Pavo cristatus.
Sexual display by a Megaselia female.

Display is a form of animal behaviour, linked to sexual selection and survival of the species in various ways. One example of display used by some species can be found in the form of courtship, with the male usually having a striking feature that is distinguished by colour, shape or size, used to attract a female. In other instances, species may exhibit territorial display behaviour, in order to preserve a foraging or hunting territory for its family or group. A third form is exhibited by tournament species in which males will fight in order to gain the 'right' to breed.

Among animals

Animals use display behaviors and markings as signals to other animals, usually of the same species. Although there is a great variety in the manner of display in animals, they are usually meant as honest advertisements of the health, vigor, and/or toxicity of the possessor. Within a species, these are typically seen in the competition for mates. This can be either through intimidation of same-sex rivals, or wooing of the females or both. An example of wooing-style courtship display is the nest a male bowerbird builds to attract females. Other animals, such as fiddler crabs, advertise the size of their enlarged claw to intimidate their rivals. As mentioned, animals may also use display behavior during direct competition between them for a resource other than mates. In animals that are so well-armed by the nature of their ecological niches, a physical confrontation may equal death for one or all of those involved. In these cases, using a display behavior that allows the animal to estimate the opponent's fighting ability, may save the costs and risks of fighting an unnecessary battle. Examples of this behavior may be found in the world of beetles, birds, mammals and more.

Among humans

Humans typically advertise their suitability as mates in acquiring wealth or fame. The Papuan big men would stage elaborate feasts to show the extent of their influence and power. The potlatches of the Pacific Northwest were held for much of the same effect.

Tournament species

Male mountain gorilla

Tournament species in zoology are those species in which members of one sex (usually males) compete in order to mate. In tournament species, most members of the competing sex never win the competitions and never mate, but almost all members of the other sex do mate with the small group of winners.

Tournament species are characterized by fierce same-sex fighting. Significantly larger or better-armed individuals in these species have an advantage, but only to the competing sex. Thus, most tournament species have high sexual dimorphism. Examples of tournament species include grouse, peafowl, lions, mountain gorillas and elephant seals.

In some species, members of the competing sex come together in special display areas called leks. In other species, competition is more direct, in the form of fighting between males.

In a small number of species, females compete for males; these include species of jacana, species of phalarope, and the spotted hyena. In all these cases, the female of the species shows traits that help in same-sex battles: larger bodies, aggressiveness, territorialism. Even maintenance of a multiple-male "harem" is sometimes seen in these animals.

Most species fall on a continuum between tournament species and pair-bonding species.

See also

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