Bowerbirds, manakins and cocks-of-the-rock are famous for their males' elaborate communal courtship displays.

The bowerbirds of Papua New Guinea and northern Australia are closely related to birds of paradise and are often found in the same vicinity.

Manakins and cocks-of-the-rock can be found in Central and tropical South America.

The mating displays of the male birds are known as "leks".

They serve two purposes.

First, they provide a forum in which each male can assess his dominance against that of his peers. This is important in species in which just a small number of males are allowed to breed.

Only male bowerbirds that own a bower will breed, and consequently there is great competition for bower sites.

Bowers are not constructed indiscriminately but in tradi-tional places, and there is much raiding and counter-raiding of partially finished ones during the building season.

Second, the leks attract the females for mating purposes. Often the glitter of many males displaying at once exerts a stronger influence on the females than the display of a single male and encourages her to watch.

During the displays, all the birds make noises to attract the females as well as intimidate the other males.

The male bowerbird accompanies his movements with a complex ventriloquial and imitative call.

Manakins produce a whirring sound by flapping their special vanelike wing feathers

A male cocks-of-the-rock make snapping noises by rapidly closing his bill.

Some cocks-of-the-rock exhibit strange display movements after bobbing and puffing themselves up like farmyard cocks. They may go into deep trances, standing still for four minutes. They then jump high into the air.

The Jivaro Indians of western Amazonia imitate these leaps in their ceremonial dances.

To draw more attention to their activities, these ground-displaying birds scrupulously clear their arenas of twigs, leaves, dead flowers and other debris.

A male manakin may even bring one or two special twigs to sit upon when he is not singing and fluttering up and down above the females.

The males and females of all the birds that perform these displays are strikingly different in appearance.

Female manakins and cocks-of-the-rock lack ornate plumage, but the males have showy feathers.

Similarly, female bowerbirds have dull brown plumage while the males are adorned with yellow and golden feathers. In some species, such as MacGregor's bowerbird, the males have crests.

The sexes of all these species only come together when it is time to mate. Once mating is completed, the female goes off on her own to build a nest, incubate her eggs, and then feed and guard her offspring.