Ostrich Facts

Key Takeaways

Ostriches are the largest birds in the world, standing up to 9 feet (2.8 meters) tall and weighing as much as 320 pounds (145 kg).
They are flightless but can run at speeds up to 45 mph (72 km/h), using their powerful legs to escape predators.
Ostriches lay the largest eggs of any living land animal, with each egg weighing about 3 pounds (1.4 kg).

The ancient Roman encyclopedist and philosopher Pliny the Elder once wrote that the ostrich, being profoundly stupid, sticks its head into a bush at the first sign of danger and considers itself invisible. Here's the truth about this magnificent, maligned bird.

To dispel the ancient libel, ostriches do not bury their heads when faced with danger--a species that did so would hardly be able to survive for more than 120 million years. They do, however, stretch their long necks flat on the ground when they sleep; from a distance, it can look as though their heads are buried.

Of the three main varieties of ostriches, only the African black ostrich (Struthio camelus domesticus) is found in captivity. They are farmed for meat, leather, and feathers in at least 50 countries and just about all climatic conditions, from Alaska to equatorial Africa. Ostriches have the best feed-to-weight ratio gain of any farmed land animal in the world and produce the strongest commercially available leather.

The ostrich's eyes are about the size of billiard balls. They take up so much room in the skull that the ostrich's brain is actually smaller than either one of its eyeballs. This may be why the ostrich, despite its tremendous running speed, is not very good at eluding predators: It tends to run in circles.

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More Ostrich Facts

Male ostriches are polygamous, but they tend the nest with a single favored mate. This hen lays about a half-dozen eggs in a shallow depression in the sand, which takes her about two weeks. Other hens then add their own eggs to the nest, and once they are finished, the favored mate chases them off. The nest owners then incubate all the eggs: The female sits on them during the day, and the male takes a turn at night.
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The ostrich's intestines are 46 feet long--about twice as long as those of a human. This enables the bird to get the most out of the tough plants it eats. To help with digestion, it also swallows sand and small stones to break down food in its gizzard. Ostriches in captivity have been known to swallow just about anything that can fit down their gullet, including bicycle valves, alarm clocks, and even small bottles.

The ostrich is the largest living bird in the world. An ostrich chick grows one foot taller each month until it is seven or eight months old. Adult ostrich roosters are six to ten feet in height and can weigh as much as 340 pounds. Because of their prodigious size, ostriches were occasionally used for riding or pulling chariots in ancient Egypt; the practice never really took off, because the ostrich has a nasty temper.

This great bird has only two toes; all other birds have three or four. Ostriches kick forward, not backward, because that's the direction in which their knees bend. Ostriches never need to drink water--some of it they make internally, and the rest is derived from the vegetation they eat.

Although the ostrich egg is the largest of all eggs, it is the smallest egg in relation to the size of the bird. A three-pound egg is only about 1 percent as heavy as the ostrich hen; by contrast, a kiwi's egg--the largest in comparison to the mother--is 15 to 20 percent of the mother bird's mass. An ostrich egg is equivalent in volume to two dozen chicken eggs.

Physiologus, an early Christian text compiled around the second century A.D. and a popular read in the Middle Ages, asserts that the ostrich incubates its eggs by staring at them. It was widely held at the time that vision was the effect of special "seeing" rays emanating from one's eyes; thus, the heat in the gaze of the ostrich hatched its chicks. The author of Physiologus presents this as an allegory to inspire worshippers to keep their eyes on Christ.

This article was adapted from "The Book of Incredible Information," published by West Side Publishing, a division of Publications International, Ltd.

Frequently Asked Questions

How do ostriches adapt to their hot, arid environments?

Ostriches have adapted to hot, arid environments by being able to withstand high temperatures and conserve water. They have specialized nasal passages that reduce water loss, and they can go without water for several days, obtaining moisture from the plants they eat.

What social behaviors do ostriches exhibit in the wild?

In the wild, ostriches live in groups ranging from 5 to 50 birds, which helps them detect predators more efficiently. They also engage in complex mating rituals, where males perform elaborate dances to attract females.