Beaks are also used for preening and for nest-building. Several birds, such as storks, use their beaks in courtship. Birds' nesting and breeding patterns vary greatly. Others build communal nests with each couple having a separate space. Some lay eggs without nests, and some use the nests of other species.
Most birds are monogamous.
That is, during the nesting cycle, mating takes place only between a single pair, and the pair then shares the feeding and care of the young. Swans and eagles are among the species that form lifelong pair bonds. The Santa Ana Zoo is home to one type of bird that does not fly. The rhea, found in the South American exhibit, is related to the ostrich and is unable to fly. If you look closely, you will see their wings are too small for their body and are unable to support their body weight.