The Fayu are an ethnic group that live in an area of swampland in New Guinea. When first contacted by westerners they numbered about 400; a number reduced from about 2000 due to violence within the group. The Fayu generally live in single family groups with gatherings of several such groups once or twice a year to exchange brides. Two books have been written about living among them by Sabine Kuegler and the group are used as an example of a band type society in Jared Diamond's Guns, Germs, and Steel: The Fates of Human Societies.