Vertebrate Zoology: A Study Guide - T. A. Dauda 2014

Multicellular Animals
Class Aves
Superorder Paleognathae, or Ratites — Order Struthioniformes (African Ostriches)

The superorder Ratitae comprises flightless birds that move on land by walking or running. Their wings are poorly developed, and the Sternum is small and lacks a keel. Their hind limbs, which serve as the sole means of locomotion, are powerfully built. The feet typically bear 2 or 3 toes. There is no uropygial gland, feathers are not differentiated into distinct groups, and the barbs lack interlocking hooks.

Ratite birds inhabit Africa, Australia, South America, and New Zealand. The superorder is divided into four orders: Struthioniformes (ostriches), Rheiformes (rheas), Casuariiformes (cassowaries and emus), and Apterygiformes (kiwis).

African ostriches are distributed across the steppe and desert regions of Africa. Adult males can reach heights of up to 275 cm and weigh up to 50 kg, sometimes even 90 kg. The plumage of males is black, while females are brownish-gray, with white tails and wings (Fig. 40). Their wings are large and are spread out when the bird runs at high speeds, during which the stride length reaches 2-3 m. Each FOOT has only two toes. A long neck and acute eyesight enable the African ostrich to spot danger from afar. They generally feed on plant matter, occasionally eating small animals such as insects, reptiles, and rodents.

African ostriches typically graze and roam in small groups consisting of one male and 3-5 females. During the breeding season, the male builds a nest, into which several females lay 7-9 eggs each, resulting in a total clutch size of 15-60 eggs. The eggs are large, weighing 1.5-2 kg. The male incubates the eggs at night, and the female during the day. The chicks are precocial: they hatch with open eyes, covered in down, and are able to follow their parents shortly after birth.

Class="center">

Fig. 40 Ratite birds:

1 — African ostrich; 2 — kiwi; 3 — rhea; 4 — emu; 5 — cassowary.

Ostriches are hunted for their white tail and wing feathers, which are used for decoration, and for their meat. African ostriches are also farmed under semi-domesticated conditions.