Trumpeters: Psophiidae

Trumpeters are found in large groups which include a single dominant female and several males whom she breeds with, as well as their young. All adult trumpeters participate in feeding and caring for the young. This reproductive system, which is rare among birds, is known as cooperative polyandry (PAH-lee-andree). As with many species where many individuals live together, dominance relations, a system where some individuals have higher rank and others have lower rank, are well established among individual trumpeters. Subordinate individuals in the group, those with lower rank, often crouch and spread their wings in front of the dominant individuals. Trumpeters also preen each other, or clean each other's feathers, feed each other, and engage in mock fights. All these behaviors help to strengthen bonds between individuals in the group.

Groups of trumpeters are highly territorial, defending their territories against other trumpeters. In order to find enough food during the dry season, trumpeter groups require large territories. When a group of trumpeters finds other trumpeters in their territory, they sneak up on the intruders, then scream the loud, distinctive calls which give trumpeters their name. Fights involve kicking and pecking, and continue until the intruders leave the territory. At night, trumpeters roost in trees, sometimes in branches as high as 30 feet (9 meters) off the ground. Even at night, trumpeters make their loud territorial calls every few hours.

A single dominant female in the trumpeter group mates with as many as three dominant males. All adults help to feed and care for the young. Trumpeters like to build their nests in tree cavities, holes in trees which have been dug and abandoned by other birds. The nest is built from sticks. Before the act of mating takes place, the male feeds the female. The female then walks in a circle showing her back end while the male follows. Generally, the female lays three white eggs at a time. All the adults help incubate, or sit on, the eggs until they hatch, although the majority of the incubation is performed by the female and the dominant male. Chicks depend on adults to feed them for several weeks. They are unable to fly at first, so roost, or spend the night, close to the ground rather than high in trees like adult trumpeters. Because of this, many are eaten by snakes, predatory birds, and other species. Only about half the trumpeter chicks that hatch survive to become adults.