Alpha (biology)

In social animals, the alpha is the individual in the community with the highest rank. Where one male and one female fulfill this role, they are referred to as the alpha pair (the term varies when several females fulfill this role – it is extremely rare among mammals for several males to fulfill this role with one female). Other animals in the same social group may exhibit deference or other symbolic signs of respect particular to their species towards the alpha.

The alpha animals are given preference to be the first to eat and the first to mate; among some species they are the only animals in the pack allowed to mate. Other animals in the community are usually killed or ousted if they violate this rule.

The term "alpha male" is sometimes applied to humans to refer to a man who is powerful or in a high social position. Alpha female is used to indicate a highest-status female, whether actual or self-proclaimed. It is also used to explain the conduct of several adolescents that compete openly to call more attention, often being hostile.

Position of the alpha within the community
The status of the alpha is often achieved by means of superior physical prowess. The individual in the alpha position usually changes when another challenges it to a fight (in some species to the death) and wins. Consequently, alphas may have to fight individuals in their own group several times to maintain their position throughout their lifetimes. In species where the fight is to the death, alphas rarely reach old age. In some species, a nomadic individual may approach the alpha, successfully beat him, and thus become the new alpha. When this occurs in lions, the new alpha usually kills the previous alpha's cubs. In lions, several individuals may share alpha privileges in what is known as a coalition.

The social group usually follows the alpha to the hunt and to new breeding or resting grounds. The alpha is thus sometimes seen as deciding the fate of the group. If two groups of the same species find themselves competing for the same ground, they may let the alphas fight, letting the outcome decide which group stays.

Beta and omega
Social animals in a hierarchic community have a certain rank. Three of these ranks have attracted special attention in ethology and been given special names: alpha, beta and omega.

A beta animal is an animal that will act as a new alpha animal if the old alpha dies. In some species of birds, the males pair up in twos when courting, the beta male aiding the alpha male. The beta male does generally not get to mate with the female birds, but if the alpha dies, he takes over the alpha's females, becoming the new alpha.

Omega (usually rendered ω-male) is an antonym used to refer to the lowest caste of the hierarchical society. An omega is subordinated to all others in the community. The omega is commonly the last allowed to eat.

Primates
Chimpanzees show deference to the alpha of the community by ritualised gestures such as bowing, allowing the alpha to walk first in a procession, or standing aside when the alpha challenges.

In certain highly social species such as the bonobo, a contender can use more indirect methods, such as political alliances, to oust the ruling alpha and take his place.

Gorillas use intimidation to establish and maintain alpha position.

Canids
Canines (e.g. wolves, dogs, jackals, foxes) show deference to the alpha pair in their pack by allowing them to be the first to eat and, usually, the only pair to mate. Canines use eye contact to maintain alpha position, but in order to establish their position they often have to show physical superiority, through playing or fighting. In the case of wild canids the alpha male may not have exclusive access to the alpha female; moreover, other pack members may guard the maternity den used by the alpha female; such is the case with the African Wild Dog, Lycaon pictus.