He says N. pulcher is unusual because it lives in social groups that include both breeders and helpers.

Jordan says the breeding pair can have between two to seven helpers who do tasks such as cleaning the nest, defending territory and looking after the eggs.

The helpers do not breed, instead waiting until a breeding position becomes available through the death of a more senior member of the group.

Previous genetic work has shown that N. pulcher within a group are unrelated, suggesting the young disperse to other groups.