The most distinctive bird in Africa, the flightless ostrich is also the largest bird in the world. It occurs in the wild in all dry areas in southern Africa. The breeding behaviour of ostriches, which can be up to 2 meters tall, is unusual because they use a communal nest. At night the head of the family breeds, during the day his main hen. All side hens also lay their eggs in this nest to hatch them. A nest can sometimes hold up to a hundred ostrich eggs, each of which is the size of 24 chicken eggs and weighs 1 kilogram. During the 42-day incubation period, the males emit a three-part call that can easily be confused with a lion's roar.