Mammals: Przewalski's Horse

Range: Traditionally from Manchuria to Spain. Reintroduced populations have been started in China, Mongolia, and Kazakstan in Asia Habitat: steppe, grassy deserts, and plains

Wild things!

How do you say Przewalski's horse? It's quite a tongue twister for most Americans! It is pronounced either "sheh-VAL-skee" or "per-zhuh-VAL-skee" or even "PREZ-val-skee," depending on the speaker. It is also known as the Asiatic wild horse, or Mongolian wild horse. No matter what you call it, the Przewalski's horse is the closest living relative of the domestic horse. Like their cousins the zebra and the wild ass, all horses are in the family Equidae.

There is some question about the correct scientific classification of the Przewalski's horse, however. Some experts say they are the only true wild horse, a separate species, and call it Equus ferus. Others say it is a wild subspecies of today's domestic horse, like the Chincoteague pony, the West's mustang, and Australia's brumby, naming it Equus caballus. Much genetic research has been done, but it has been mostly inconclusive. The question will be answered with certainty only when a common ancestor of wild and domestic horses is found.

A horse, of course!

Regardless of its classification, the Przewalski's horse is very definitely a horse. It is stocky and short and pot-bellied in comparison with its domestic and wild cousins, with a spiky mane like a zebra and striped legs like the Somali wild ass. Coats vary in coloration, but all Przewalski's horse have light bellies and darker backs, with a long, dark, "eel stripe" on the back from the withers to the base of the tail. Unlike their horsey cousins, though, they don't have the lock of hair on the forehead, called forelocks. The pony-like head is rectangular and large in comparison with the rest of the body, and the ears are darkly rimmed.

Like their relatives, Przewalski's horses are grazers and mostly nibble on wild grasses. The horses at the San Diego Zoo Safari Park graze in their enclosures but are also fed alfalfa, hay, and carrots.

Social ties

It is thought that the Przewalski's horse has never have been successfully domesticated. They live in two kinds of large, distinct social groups: harem groups and bachelor groups. Harem groups rarely have more than 10 mares (females) and their offspring up to two or three years of age, led by one dominant stallion (male). Foals (babies) are born after an 11-month gestation period, and they must be up and moving with the group about 30 minutes after birth. Foals stay with the group they were born into until they are sexually mature.

When mares are old enough to reproduce, they leave the harem group to join another. When stallions are old enough to compete with the lead stallion, they are driven out of the group and will join small bachelor groups until they are mature enough to successfully compete for a harem group of their own.

The horses graze together, rest together, and utilize a home range of 1 to 12 square miles (3 to 32 square kilometers). Group members spend a lot of time grooming one another, standing side by side, head to tail, and nibbling at one another's backs and sides. This helps to reinforce social bonds within the group and also provides a good scratch!

Built for the cold

Przewalski's horses grow thick, warm coats for the winter, complete with long beards and neck hair. Winter coats are important in the harsh winter desert, where temperatures can be freezing. In high winds, Przewalski's horses will turn their backs to the storm and tuck their tails tightly between their back legs! This may be an adaptation to help protect the eyes and nostrils, while also protecting the sensitive reproductive parts, from the severe winds and sand storms of the Gobi Desert.

Galloping ghosts

Wild horses roamed throughout Asia and Europe 20,000 to 30,000 years ago until late into the 19th century! Human populations were small until only a few thousand years ago and didn't have much of an impact on the horses. Przewalski's horses are native to a habitat called the steppe. Until 15,000 years ago, this immense and hardscrabble, sparse grassland habitat stretched from the east coast of Asia to present-day Spain and Portugal. After the last Ice Age, however, the steppe gave way to woods and forests to which the Przewalski's horses weren't well adapted. By the 19th century the few animals that remained were confined to Mongolia, southern Russia, and Poland.

In the early 20th century, farmers and livestock took over good grazing lands, forcing the wild horses into areas that weren't suitable for human use. Wealthy aristocrats and westerners were also fascinated by the unusual wild horses and captured foals to keep as pets. Wild horses were spotted in Mongolia into the 1980s. They became extinct in the wild about that same time.

Luckily, a small number of Przewalski's horses remained, scattered about in various zoos around the world. All Przewalski's horses alive today are descendants of 14 horses captured at the beginning of the 20th century.

Reintroduction efforts

In 1977, the Foundation for the Preservation and Protection of the Przewalski's Horse was founded and an exchange of animals between zoos throughout the world was started. In 1992, 16 horses were released into the wild in Mongolia, in an area that was later designated as Hustai National Park. As of 2005, the world's population of Przewalski's horses was about 1,500 animals, with 250 of those being free-ranging. New zoo-bred horses continue to be introduced to the wild population, now located in four reserves in Mongolia and Kazahkstan, as well as the Kalameili Reserve in northern China.