The scarlet ibis has a colonial and social breeding system. Nests are generally built close to one another with more than one per tree. This is most likely done to reduce the risks of predation. Males use displays of preening, flights, head rubbing, and a rocking motion to attract mates. A female must be cautious when approaching a male, because he may actually attack her if she does not remain in his display area. Scarlet ibises are polygynous, the males often mate with more than one female. They begin visiting their colonial nesting sites by mid-September and egg-laying takes place between early November through December. The first egg is laid 5 to 6 days after copulation, and there are usually 3 to 5 eggs in each nest. Eggs are not glossy, but are smooth. Chicks fledge after 35 days and are independent in 75 days.