Social animal
A Social animal is a loosely defined term for an organism that is highly interactive with other members of its species.
In practice all animals are social to some extent - sexually reproducing animals must come together to mate, and in animals showing any degree of parental care there is a minimal social unit of one or more parents and their offspring. The term "social animal" is usually only applied when there is a level of social organization that goes beyond this, with permanent groups of adults living together, and relationships between individuals that endure from one encounter to another.
Animal social behaviour and organization is studied in comparative psychology, ethology, sociobiology and behavioral ecology. Typical issues in social behaviour are:
- what is the typical size of the group, and what factors limit group size and/or lead to groups merging or splitting?
- to what extent does the species show territoriality, and if territories are maintained, what is their purpose, and are they held by an individual or a group?
- are there permanent social dominance relationships within the group, and if so, is there any pattern within them, such as the linear dominance hierarchy or "pecking order" that T. Schjelderup-Ebbe claimed to observe in chickens (in practice such linear hierarchies are rare in nature, though they commonly form in captive or domestic groups, or as a result of human interference such as the provision of artificial food supplies).
A few species, notably insects of the orders Hymenoptera (ants, bees and wasps) and Isoptera (termites) show an extreme form of sociality involving highly organized societies with individuals specialised for distinct roles. This form of social behaviour is nowadays referred to as eusociality. It has been claimed that a few vertebrate species, most notably the Naked Mole Rat are eusocial.
Some animals whose social behaviour is of particular interest:
