Helpers at the nest

Helpers at the nest is a term used in behavioural ecology and evolutionary biology to describe a social structure in which juveniles and sexually mature adolescents of either one or both sexes, remain in association with their parents and help them raise subsequent broods or litters, instead of dispersing and beginning to reproduce themselves. This phenomenon was first studied in birds where it occurs most frequently, but it is also known in animals from many different groups including mammals and insects. It is a simple form of co-operative breeding.

It occurs in between three and eight percent of bird species worldwide (estimates vary), but is much more common in Australia and Southern Africa. Bird species in which this behaviour is found include the common moorhen, the acorn woodpecker, and the apostlebird. The sugar glider and humans are examples of mammals that exhibit this behaviour. It is also seen in a number of species of bee such as carpenter bees (note this is distinct from the behaviour of the European honey bee, where the worker bees are sterile and incapable of reproducing).

The term "helper" was coined by Alexander Skutch in 1935 and defined more carefully in 1961 in the avian context as "a bird which assists in the nesting of an individual other than its mate, or feeds or otherwise attends a bird of whatever age which is neither its mate nor its dependent offspring." The term has been criticised as being anthropomorphic, but it remains in use.

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