Is an Okapi a Zebra? The Giraffe's Striped Forest Cousin

What kind of animal is an okapi?

The okapi (Okapia johnstoni) is a hoofed mammal of the order Artiodactyla, the even-toed ungulates, which also includes deer, cattle, antelopes and giraffes. Like them, it walks on two toes per foot, each capped with a hoof, and it is a ruminant that chews the cud.

Within that order, it belongs to the family Giraffidae. Millions of years ago this family included many species across Africa, Europe and Asia, some with short necks much like the okapi. Today only two lineages survive: the okapi in the Congo rainforest and the giraffe on the African savanna. Genetic studies suggest the okapi and giraffe lines separated roughly 11–12 million years ago.

How is an okapi different from a zebra?

Zebras such as the plains zebra are members of the horse family, Equidae, in a completely different order, Perissodactyla, the odd-toed hoofed mammals. A zebra stands on a single hoof per foot, while an okapi has a split, two-toed hoof. The two groups have been evolving separately for tens of millions of years.

What does an okapi share with a giraffe?

Several features tie the okapi firmly to the giraffe. The most obvious are the ossicones: short bony knobs on a male okapi’s forehead that are covered in skin and hair, unlike the bare horns of cattle and antelopes or the shed antlers of deer. Giraffes are the only other living animals with ossicones.

The okapi also has a long, dark, prehensile tongue, about 35–46 cm (14–18 in) long, which it wraps around branches to strip off leaves, just as a giraffe does. It is long enough for the okapi to clean its eyes and ears. Both animals walk with a pacing gait, moving the front and back legs on the same side at the same time. They also share details of the skull and teeth that anatomists used to classify the okapi as soon as a skull reached Europe.

Why does an okapi have stripes?

The okapi’s stripes are found only on its hindquarters and upper legs, with white stockings below. In the dappled light of the rainforest floor, the broken pattern of dark and light helps blur the animal’s outline, making it harder for predators such as leopards to spot. This kind of disruptive camouflage is the most widely accepted explanation.

A second, frequently suggested idea is that the bright rump stripes help a calf recognize and follow its mother through dense vegetation. This is plausible but has not been firmly tested in the wild, where okapis are very hard to observe. The stripes are a good example of convergent evolution: similar-looking patterns appearing in unrelated animals. Zebras’ stripes may serve quite different purposes; current research on those is summarized in Why do zebras have stripes?

How was the okapi discovered?

The okapi was well known to the peoples of the Congo forests, but outsiders only learned of it at the end of the 19th century. Explorers’ accounts mentioned a mysterious forest animal, and in 1900 British colonial official Sir Harry Johnston heard about it from Mbuti people of the Ituri Forest. They described a horse-like creature, but the tracks they showed him had two toes, not one.

Johnston obtained strips of striped skin, which seemed to confirm that it was a forest zebra or horse. In 1901 the animal was formally described as Equus johnstoni, placing it in the horse genus. When a complete skin and skulls arrived, the error became obvious: the skull clearly belonged to a giraffid. The species was moved to its own genus, Okapia, and has been known as the okapi ever since.

Why do people confuse okapis with zebras?

Most people see okapis only in photos or zoos, where the striking white leg stripes catch the eye first. Nicknames such as “zebra giraffe” add to the confusion, and some websites even describe the okapi as a cross between a zebra and a giraffe, which is false.

Seen as a whole, though, the okapi looks far more like a short-necked giraffe than a zebra: a sloping back, large ears, a long face and, in males, ossicones. To see where these animals live in the wild, read Where do okapis live?