- CLASS: Mammalia (Mammals)
- ORDER: Perissodactyla
- FAMILY: Equidae
- GENUS: Equus
- SPECIES: asinus
- SUBSPECIES: somalicus
Wild horses? Sleek, graceful, proud, and majestic, wild members of the horse family Equidae (horses, zebras, and wild asses) have long held a strong fascination for humans. All wild asses differ from horses and zebras in their smaller size, larger ears, tufted tail, stiff mane, and characteristic loud bray. Found in some of the most unlivable habitats of Africa and Asia, wild asses are able to eke out a living and thrive where most animals could not. African wild asses are divided into two subspecies: Somali and Nubian wild asses. Until recently, both were found in the wild, but it is possible that only the Somali wild ass remains.
All wild asses have bristly upright manes like their zebra relatives. The Somali wild asses have a soft gray body, white belly, spiky black-and-gray mane, and unique black- and-white stripes on their legs that also hint of their family connections! Their short, smooth coat has a purplish hue when the light hits it just right.
The smallest of the equids and the only ass with striped legs, the Somali wild ass has small, narrow hooves that help the animal move quickly and safely through its stony habitat. This small, surefooted design led to the domestication of Nubian and Somali wild asses by the Egyptians more than 6,000 years ago!
Somali and Nubian wild asses have been an important part of Africa's history. Their images have been painted in caves by ancient peoples in North Africa, and, at one time, sultans of the area ordered a man's hand cut off if he killed a wild ass.
Wild asses are intelligent creatures, with excellent vision and hearing. They'd rather run from predators than fight. If cornered, though, they can kick hard to protect themselves. One swift kick from the business end of a sharp hoof is enough to drive away most predators, such as wolves!
HABITAT AND DIET
Somali wild asses have to deal with extremely high temperatures. Native to the rocky desert of eastern Africa, the animals rest under any shade they can find until the temperature cools down in the late afternoon and evening, grazing again in the early morning hours.
All wild asses are herbivores and spend their time grazing on grasses, but they also eat scrub, bark, and tough desert plants. Their upper and lower incisor teeth clip grass and other vegetation. Molars help to grind the rough food before swallowing.
Somali wild asses at the San Diego Zoo Safari Park are fed hay, alfalfa, carrots, and herbivore pellets. Even though they are very well adapted for life in the desert, they must live near a water source and need to drink to survive.
Somali wild asses often live alone due to the lack of food in the deserts where they are found. Small herds do exist, though, usually comprised of mares (adult females) and their offspring. Occasionally, larger groups form during the wet season when food and water are more plentiful. This is also when foals are born almost a year after mating takes place.
Stallions (adult males) are often solitary, and mature stallions are known to protect territories that usually include a water source. It's good to be the only stallion around when the mares come down to the water hole for a drink!
Stallions often fight each other in bitter battles that include rearing and biting, all for the right to breed with the females. The mares give birth to a foal about 11 months later. Like domestic horses, foals in the wild ass herd like to chase, neck wrestle, rear, buck, and leap. It is quite fun to watch!
Somali wild ass foals (babies) are able to follow their mother within a few hours after birth, and usually by the time they are one year old, they are half grown, weaned, and no longer need their mother.
Like all equids, wild asses grow long, dense winter coats to protect them from the cold. In the spring, they begin to molt, losing the hair in patches. To help the molting process along, two animals may stand side by side and head to tail, nipping at each other's sides and neck. The animals also roll, bite, and scratch at their own coats to keep their skin in good condition.
AT THE ZOO
Over the years, the San Diego Zoo Safari Park has been one of the best zoo locations for wild asses, and we’ve celebrated many “firsts” in the zoo world with them. Somali wild asses first came to San Diego from the Basel Zoo in Switzerland in 1981; in 1986, a foal was born, the first captive reproduction in the Western Hemisphere. Today, the Safari Park is one of only a few places in the United States that has Somali wild asses, and we have welcomed the births of 43 more foals, including 3 foals born in 2011. We currently hold more than any other zoo in North America.
A habitat featuring the rugged terrain and naturally occurring boulders at the Safari Park was opened for Somali wild asses in 2010. Watch for them during an Africa Tram tour at the Safari Park.
All wild equids—horses, zebras, and wild asses—are threatened; however, the Somali wild ass is critically endangered. Political unrest, encroachment of their land and water sources by domestic herds, poaching, and a general lack of concern for their welfare are all major threats to the wild asses. The animals compete with people and livestock for food and water sources; they are hunted for food, skins, and use in traditional medicines; and they can also freely interbreed with domesticated donkeys, which further threatens the species.
The Somali wild ass is the smallest of all the equids and is at critical risk, with only a few hundred left in the wild. Something as simple as a drought could be enough to wipe out the species completely. Protected by the local government, Somali wild asses are still hunted for meat or for their fat, which is used medicinally and is believed to cure hepatitis. Another problem is hybridization; local people leave their female donkeys beside water holes at night, hoping Somali wild ass stallions will mate with the donkeys to improve the domestic breed. This is a serious threat to the gene pool of the wild species.
The Nubian wild ass may be extinct in the wild already, and there are none in zoos at this time.
San Diego Zoo Global participates in a Species Survival Plan for equids to help keep these species alive and well. Our San Diego Zoo Safari Park is one of only a few breeding facilities in the United States that maintains wild asses and has welcomed the births of numerous Somali wild asses, more than any other zoo in North America. We are working on a project to determine which factors impact reproductive success in this species.
We are also working on a project to document social behavior, activity budgets, nursing behavior, and behavioral development of foals and are working in collaboration with the St. Louis Zoo to examine hormone levels in relation to reproductive success.