Individuals in viscous populations (with limited dispersal) live in close proximity with kin, allowing for cooperation among relatives. However, there might also be costs, like risk of inbreeding and competition for space and resources. In 2008 I set-up a new field based study system on cooperatively breeding red-winged fairy-wrens (Malurus elegans). The fairy-wren genus is well known for their extremely high levels of promiscuity. All 9 Australian fairy-wren species are cooperative breeders with males staying with their parents to help rear the next brood. In my study species females too stay at home. The extreme philopatry of both sexes make M. elegans ideally suitable to study both the costs and benefits of living in close proximity with kin.