Male "silverback" gorillas are usually the alpha animal and may receive preferential treatment such as being groomed by other group members
In studies of social animals, the highest ranking individual is sometimes designated as the alpha. Males, females,
or both, can be alphas, depending on the species. Where one male and
one female fulfill this role together, they are sometimes referred to as
the alpha pair. Other animals in the same social group may exhibit
deference or other species-specific subordinate behavior towards the
alpha or alphas.
Alpha animals usually gain preferential access to food and other
desirable items or activities, though the extent of this varies widely
between species. Male or female alphas may gain preferential access to
sex or mates; in some species, only alphas or an alpha pair reproduce.
Alphas may achieve their status by superior physical strength and aggression, or through social efforts and building alliances within the group, or more often, simply by breeding and being the parent of all in their pack.
The individual with alpha status sometimes changes, often through
a fight between the dominant and a subordinate animal. These fights are
often to the death, depending on the animal.
Beta and omega
Social animals in a hierarchical community are sometimes assigned ranks in ethology studies.
Beta animals often act as second-in-command
to the reigning alpha or alphas and will act as new alpha animals if an
alpha dies or is otherwise no longer considered an alpha. In some
species of birds, males pair up in twos when courting, the beta male
aiding the alpha male. It has been found that the social context of the
animals has a significant impact on courtship behavior and the overall
reproductive success of that animal.
Omega has a conflicted meaning. As an antonym
it is used to refer to the lowest caste of a hierarchical society.
Following the theories that omega animals are subordinate to all others
in the community, and are expected by others in the group to remain
submissive to everyone. Omega animals may also be used as communal
scapegoats or outlets for frustration, or given the lowest priority when
distributing food.
These same researchers also compared the omega wolf to a "court
jester," being first to initiate play, and while submissive, well liked
and not outcast. Interestingly, in the pack under study, the omega named
Lakota was in fact the largest and strongest of the wolves.
Alternately, and in popular use, is the omega as the romanticized "Lone Wolf" or the omega wolf as discussed by David Mech.
Per this pro-omega type, the omega is not the submissive “second place”
as a beta is. Rather, they are equally dominant yet in an independent
way. Instead of leading a group like an alpha or collaborating like a
beta, this omega type is self-reliant, and less collaborative — but also
less focused on leading or commanding groups.
Examples
Primates
Common chimpanzees use strength, intelligence, and political alliances to establish and maintain alpha position.
Alpha males who solely use intimidation and aggression to keep their
position often provoke dissent. Coalitions will eventually form, which
at some point will topple the alpha male. There have been rare cases where a group has killed the alpha male.
Common chimpanzees show deference to the alpha of the community by
ritualized postures and gestures such as presenting their back,
crouching, bowing, or bobbing. Chimpanzees lower in rank than the alpha male will offer their hand while grunting to the alpha male as a sign of submission. Bonobo
society on the other hand is governed by alpha females. Males will
associate with females for rank acquisition because females dominate the
social environment. If a male is to achieve alpha status in a bonobo
group, he must be accepted by the alpha female.
Female bonobos use homosexual sex to increase social status.
High-ranking females rarely interact sexually with other females, but
low-ranking females interact sexually with all females.
Gorillas use intimidation to establish and maintain alpha position. A study conducted regarding the reproductive behavior of male mountain gorillas (Gorilla beringei beringei) found further evidence that dominant
males are favored to father offspring, even when there is a greater
number of males in a notably enlarged group size. The study also
concluded that mating access dropped off less steeply with status;
alpha, beta, and gamma showing more similar mating success, compared to what had been previously thought.
A study on the association of alpha males and females during the
non-breeding season in wild Capuchin monkeys (Cebus apella nigritus)
examined whether alpha males are the preferred mate for females and,
secondly, whether female-alpha status and relationship to the alpha-male
can be explained through the individual characteristics and or social
network of the female.
The results indicated that alpha male Capuchin are the preferred mate
for adult females. However, only the alpha females had strong
interactions with the alpha males by virtue of a dominance hierarchy among the females in which only the most dominant and strong females were able to interact with the alpha male.
Researcher M.W. Foster
investigated primates and found that the leaders were more likely to be
those who did more for those around them instead of being determined by
strength.
Canines
In the past, the prevailing view on gray wolf
packs was that they consisted of individuals vying with each other for
dominance, with dominant gray wolves being referred to as the "alpha"
male and female, and the subordinates as "beta" and "omega" wolves. This
terminology was first used in 1947 by Rudolf Schenkel of the University of Basel, who based his findings on researching the behavior of captive gray wolves. This view on gray wolf pack dynamics was later popularized by the researcher L. David Mech in his 1970 book The Wolf.
He later found additional evidence that the concept of an Alpha male
may have been an interpretation of incomplete data and formally
disavowed this terminology in 1999. He explained that it was heavily
based on the behavior of captive packs consisting of unrelated
individuals, an error reflecting the once prevailing view that wild pack
formation occurred in winter among independent gray wolves. Later
research on wild gray wolves revealed that the pack is usually a family
consisting of a breeding pair and their offspring of the previous 1–3
years. In the article, Mech wrote that the use of the term "alpha" to
describe the breeding pair adds no additional information, and is "no
more appropriate than referring to a human parent or a doe deer as an
alpha." He further notes the terminology falsely implies a "force-based
dominance hierarchy." In 13 years of summer observations of wild wolves,
he witnessed no dominance contests between them.
In some other wild canids, the alpha male may not have exclusive access to the alpha female. Other pack members as in the African painted dog (Lycaon pictus) may guard the maternity den used by the alpha female.
