The Ostrich is a Ratite

The Ratites

A little lesson on ratites. A ratite is any bird whose sternum (breastbone) is smooth, or raftlike, because it lacks a keel which is required for the anchorage of the main flight muscles, so these are flightless birds The ratites include some of the largest birds of all time, such as the moa and the elephant bird (Aepyornis). Living today are the ostrich, emu, cassowary, rhea, and kiwi.

It was once thought that the ratites evolved from a common flightless ancestor and split into different groups on different continents about 50 – 65 million years ago. But since they cannot fly, how did they get so dispersed? The answer comes from DNA. They didn’t disperse from a common ancestor, they got to their present geographic locations by flying there and only later lost their power of flight.

Let’s look at the most well-known and largest of ratites, the African Ostrich. Nearly 9.2 ft tall and weighing as much as 344 lb, its name comes from the Old French ostriche. Its scientific name, Struthio camelus, literally means camel sparrow, from the Ancient Greek strouthiokámēlos. As its species name suggests, the ostrich was once known as the “camel bird” because of its long neck, prominent eyes, and sweeping eyelashes, as well as its jolting walk. Also, like camels, the ostrich can tolerate high temperatures and go without water for long periods of time.

Black-feathered male Ostrich with two females

Unlike most birds’ feathers, ostrich feathers are loose, soft, and smooth. They don’t hook together the way feathers of other birds do, giving Ostriches a “shaggy” look. The feathers can also get soaked in the rain, because ostriches do not have the uropygial gland many birds have to waterproof their feathers while preening. Ostrich feathers have been used to decorate the hats of military officers, and  royalty, and even King Tut was buried with a gold fan containing Ostrich feathers. Marie Antoinette, who is accused of initiating the enormous popularity of bird feathers on hats, starting the feather trade which decimated many bird populations wore Ostrich and Peacock feathers on her hats. At that time a pound of Ostrich feathers garnered $750 on the market.

Weighing in at more than 3 pounds, the ostrich egg is the largest egg—in fact, the largest single cell. Only dinosaurs produced larger eggs. One ostrich egg is equivalent to the weight of about 24 chicken eggs and over 4000 hummingbird eggs could fit into one Ostrich egg! Bushmen of the Kalahari used them to carry water. The content of the eggs was blown out, the hole sealed with grass, and the eggs with water carried in an especially designed bag. They were often decorated and today you can find examples of them in various museums. Today, in various craft and souvenir stores in parts of Africa you can purchase heavily decorated Ostrich eggs.

An ostrich nest may contain up to 80 eggs, but only a few are laid by the dominant pair. Lesser ranked females add their eggs to the nest but only a few are incubated by the dominant pair, which means only a few hatch.

Ostriches are declining in their native habitat due to overhunting and habitat destruction, but many are farmed, being used for meat low in fat and cholesterol, eggs, and feathers.

4 thoughts on “The Ostrich is a Ratite

  1. Can you recommend any good illustrations depicting the keel-less ratite sternum compared with a sternum that has a keel. Thank you for the interesting and informative article and for your reply.

  2. Hi Roger, great info – an added source publication would be appreciated
    With many thanks and my very best regards, Thomas

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