The ostrich’s long, powerful legs allow it to look over the top of tall vegetation when scanning for predators, and also to cover great distances in search of food. The fastest runner of any bird, it can reach up to 70 kilometres per hour in short sprints, with strides of 3 to 5 metres in length, more than compensating for its lack of flight. It is also able to outpace most mammals in terms of stamina, capable of running at up to 50 kilometres per hour for 30 minutes or more (2) (5). The diet of the ostrich includes grasses, seeds and leaves, as well as flowers, fruit and roots. The leaves, flowers and fruits of succulent plants are important in drier areas, and some insects and small vertebrates may also be taken (2) (5) (8). Ostriches typically feed in groups, browsing close to the ground (2), although S. c. molybdophanes is said to be more solitary (4).
The breeding season and strategy of the ostrich vary with location (2). Where food is scarce, breeding pairs tend to be monogamous, but elsewhere breeding groups usually form, consisting of a territorial male together with a main or “major” hen and several secondary, “minor” hens (2) (5). At the start of the breeding season, the male scrapes out a nest, a mere depression in the ground, and then attempts to attract females using an elaborate courtship display (2) (4), which involves dropping to the ground, opening the wings and tail, shaking each wing alternately, and moving the tail up and down, while swaying the head and neck from side to side. The male will then approach the female with the wings open and the brightly coloured neck puffed out, while stamping the feet (2).
After mating, the main female lays up to 11 creamy white eggs, while the other females lay around 2 to 6 eggs each, in the same nest, and may also lay eggs in other nests (2) (4). The egg of the ostrich is the largest in the world, although relatively small in relation to the size of the bird, at around 16 centimetres in length and 1.5 kilograms in weight, with a 2 millimetre thick shell. Incubation is performed only by the male and the main female, and lasts between 42 and 46 days. Any surplus eggs which the pair cannot cover are pushed out of the nest by the female, who is somehow able to recognise and retain her own, leaving about 20 eggs in total (2) (4). The young are buff-coloured with black lines and specks, and leave the nest within the first three days. The pair may sometimes take chicks from other broods, and large crèches often form, escorted by one or more adults. The adult birds may attack potential predators when defending the young, and have even been reported to kill lions with a kick. The young ostriches fledge at 4 to 5 months and are fully grown by about 18 months, reaching sexual maturity after 3 to 4 years and potentially living for up to 30 to 40 years (2).