centrally concentrated leks, demonstrating active female choice. Nesting Unlike other species of the family Cotingidae, the Guianan cock-of-the-rock makes its nest on rocky cliff faces and caves rather than in the trees. The female lays one or two eggs in the nest of mud and plant material, which is attached by saliva to a vertical rock. The female takes care of the building and maintenance of the nest, the incubation of the eggs and the parenting. The male does not participate at all. Eggs typically incubate for 27–28 days. The ideal nesting sites for this species are usually located in a cave or vertical rock face with crevices that provide some shelter and protection from the elements. The nests themselves are solid moldings formed from mud and plant material deposited into the crevices. Due to the solid nature of these nests, they typically persist from one breeding season to the next. Females will make repairs to their nests as a breeding season begins. Mating behavior The smaller of the two cocks-of-the-rock, the male Guianan takes the lesser part in breeding. It is polygynous and has nothing to do with nesting once mating is done. The male's energy instead is devoted to very elaborate display rituals that show off his magnificent plumage. These displays take place in communal leks, where 40 or more males may gather to challenge rivals and beckon to the females. The displaying male purposely contrasts himself from the forest, shows his crest and plumage so much that the bill and tail become obscured; almost making him difficult to recognize as a bird, to attract females. Within the lek, each female has her own perch on a low branch, while the males own a "court" on the ground below that is cleared of dead leaves by the draughts of each male taking off and landing. The males have a variety of calls and movements, showing off the crest, elongated filaments on the rump, secondary feathers, and the snapping of their bills. Males display on branches about from the ground until a female approaches, when the males display and call from individual plots on the ground. Most males copulate with only a few females. However, some are very successful and may copulate with many. Unlike many other bird species, the male does not use resources nor parental care to entice females. Males often engage in courtship disruption practices. In