In the course of evolution, many birds lost their ability to fly. Although gigantism and flightlessness are almost exclusively correlated, many small domesticated birds like chicken and duck have also lost the ability to fly for an extended period, despite their ancestral species like the red jungle fowl and mallard, have that ability. With a height of 9 feet (2`75 m) and weighing around 150 kg, the Ostrich is not only the largest among the flightless birds, but also the largest and heaviest bird in the world, which lays the largest eggs of any living land animal. Categorized as Struthio camelus, the ostrich was once probably known as the Camel bird for its long neck and legs, prominent eyes with sweeping eyelashes, jolting walk, the capability to tolerate high temperature, and the ability to go without water for a prolonged period.

The feathers of the ostrich are loose, soft, and smooth, but as their feathers lack the tiny hooks that lock together the smooth external feathers of flying birds, they have a shaggy look. Their feathers get soaked in the rain as they do not have the special gland, like many other birds, to waterproof their feathers. While the adult male is strikingly black with white plumes in the wings, the adult females have grayish-brown feathers. The head, neck, and legs, including the powerful thighs, of both male and female ostriches are bare. Their legs, each two-toed foot equipped with a long and sharp claw, can also be formidable weapons. The powerful kick of an ostrich can kill even a potential predator like a lion, let alone a human.

Even though the ostriches are flightless birds, they cover their bare skin of the upper legs and flanks using their wings or leave the areas bare to release heat. They also use their wings as rudders to change their direction while running. The ostriches are flightless birds, but they are built to run. With their powerful, long legs, they can cover 10 to 16 feet in a single stride, can sprint in short bursts up to 43 miles per hour (70 km), and can maintain a steady speed of 31 miles (50 km) per hour.

Habitats of the dry, hot savannas and woodlands of Africa, the big birds are omnivorous. Although they mostly eat plants, roots, leaves, and seeds, they also munch on insects, lizards, rodents, and snakes that come within their reach. As they eat, their food is primarily dumped in the pouch at the top of the throat, and as it becomes a large lump, it slides down the throat.

Habitats of the dry, hot savannas and woodlands of Africa, the big birds are omnivorous. Although they mostly eat plants, roots, leaves, and seeds, they also munch on insects, lizards, rodents, and snakes that come within their reach. As they eat, their food is primarily dumped in the pouch at the top of the throat, and as it becomes a large lump, it slides down the throat. Strangely, the ostriches even swallow sand and pebble, and that help to grind up food stored in the ventriculus pouch. They drink if they find a watering hole, but they do not actually need to drink as they get all the water they need from the plants.

The ostriches live in nomadic groups of usually less than a dozen birds with a dominant male that maintains the herd, defends his territory, and mate with the dominant hen of the group. However, the male sometimes mates with the other females in the group, and other wandering males may also mate with them. To draw the attention of the female, the male bird bow and flap their wings outward and display their plumage and its beak and shins turn crimson. Sometimes the neck also turns red. If the female agrees to mate, her feathers will turn to a silvery colour.

The dominant hen and male take their turns incubating the giant eggs, the largest in the world, each averaging about 6 inches in length, 5 inches in diameter, and weighing around 1`35 kg. The new chicks are fawn in colour, with brown spots. During the first year of life, they grow at a rather galloping rate of about 9.8 inches per month. While they become sexually mature between two and four years, their lifespan is up to 40 to 45 years.