Geographical Range Kenya (in East Africa)
Habitat Dense mountain forests
Scientific Name Tragelaphus eurycerus isaaci
Conservation Status Endangered

Hope on the Horizon

Unlike the more common bongo, the mountain bongo is an endangered subspecies of antelope that lives only in a few pockets of mountain forests in Kenya. It is such a rare animal that it has not been seen in much of its natural habitat in nearly a decade. But thanks to zoos like ours, efforts are now underway to re-establish healthy groups of mountain bongos in the wild.

Stripes and Horns

The bongo is the largest of the forest antelopes. Its body is heavily built and stocky. Although a male usually stands no higher than four feet at the shoulder, he can weigh up to 900 pounds.

This beautiful antelope's coat is a glossy, chestnut color, ringed with an average of 12 to 14 narrow white stripes on the shoulders, flanks and hindquarters. The bongo has a dark-and-white crest of hair running the length of the spine, and often sports a yellowish-white band between the eyes, and two large white spots on each cheek.

The bongo's coloring probably serves to camouflage the animal in its dense forest home. But scientists also think the distinctive stripes may help the antelopes identify one another in their dark habitat.

Bongos have sturdy, spiraled horns that resemble those of their cousins: nyalas, sitatungas, bushbucks, kudus and elands. Bongos are the only spiral-horned antelope in which both sexes have horns, though the males' horns are heavier and longer than the females'. The horns extend up and along the back, giving the animal a "hunched" appearance.

Despite their large horns, bongos can run amazingly fast and gracefully through thick forest cover. They do this by tilting their chin up, causing the horns to lie flat against their back. This happens so frequently that older animals often rub bald spots on their back with the tips of their horns!

Browsing Bongos

Since bongos are large animals, they require a large amount of food each day. So they live only in areas with abundant year-round growth of herbs and low shrubs. That probably accounts for the animal's limited range.

Bongos are browsers. They especially like the tender bushes that grow at the base of trees. They also browse on the leaf tips, shoots, roots and vines of a wide variety of other plants including bamboo, cassava and sweet potato. They use their long, prehensile (grasping) tongue to grasp the vegetation they feed on.

Though bongos prefer browsing on low shrubs, they will sometimes reach for leaves seven to eight feet off the ground. They do this by rearing up on their hind legs and bracing their forelegs against a tree trunk. Bongos can also uproot saplings with their horns to get at the roots.

Not everything a bongo eats is good for its health. The bamboo that serves as one of the animal's major food sources can also pose a deadly threat. After the bamboo plants flower (at intervals of three to 10 years), the plants die back. During the second year of re-growth, they become toxic. Bongos are frequently poisoned by the toxic bamboo.

All Ears

As you might expect from an animal with such large ears, bongos have good hearing. They seem to rely more on their sense of hearing than on sight or smell. This helps keep them aware of predators, and keeps them in touch with other bongos in the thick forest.

The animals have only a limited number of vocalizations, mostly grunts and snorts. When they're in distress, they bleat. The females emit a weak, mooing call to contact their young.

Almost Loners

Bongos are mostly nocturnal (active at night), though they occasionally move about during the day. They are shy animals, timid and easily frightened. They either run away quickly after a scare or they seek cover, standing very still, alert and poised to flee.

Bongos don't live in large groups; in fact, they're fairly solitary animals. Mothers and their young form small groups or nursery herds. As the male offspring mature, they leave their maternal groups and live on their own. An adult will occasionally pair-off with another adult male or female, but the animals apparently have no long-lasting bonds.

Adult males who meet in the forest will occasionally use their horns in a ritual sparring contest with each other, but they rarely have a serious fight. The ritual often includes an elaborate display in which the males bulge their necks, roll their eyes and hold their horns in a vertical position, while slowly pacing back and forth in front of the other male.

Baby Bongos

Male bongos seek out adult females only at breeding season, though they don't try to herd them or restrict their movements, as do some antelope species.

After mating, a female is pregnant for about 9 ½ months. Births usually take place in December and January. When females are ready to give birth, they often go to traditional calving grounds to deliver. They give birth to a single calf, which has the same color pattern as adults but is a much lighter shade of caramel.

Baby bongos are ready to run just hours after birth. Newborns are "hiders" rather than "followers;" they lie still in the undergrowth for a week or more. Mothers return to their calf for short visits to nurse it. This behavior is an important adaptation to avoid detection by predators.

Bongo calves grow rapidly. They soon accompany their mother in the nursery herds. Their horns also grow rapidly and begin to show in 3 ½ months.

The Role They Play

The secretive habits of wild bongos make them hard to study, but scientists are beginning to learn more about the role they play in their ecosystem. As browsers, they are important in keeping forest vegetation from becoming overgrown. They also serve as a key prey species for leopards and pythons, and sometimes hyenas and lions.

Bongos are also susceptible to disease such as rinderpest (in the 1890s this disease almost exterminated the species). But today the most serious predators are people living near forests, who often hunt bongos with dogs or set snares to trap them.

Sending Bongos Back to the Wild

The number of wild mountain bongos has plummeted in the past 50 years, and the subspecies is highly endangered. The wild animals are restricted to three small sub-populations in Kenya: Aberdares Conservation Area, the Mau Forest and Mt. Kenya National Park. Altogether there are probably less than 100 mountain bongos surviving in the wild.

The animals have fallen victim to habitat destruction and hunting. Mountain bongos are so dependent on the presence of dense vegetation that they are particularly vulnerable to forest clearing, which has been on the rise in Kenya due to logging and farming.

In addition, large-scale hunting has completely eliminated bongos in some areas. Their refuges are surrounded by dense human populations. Many of these people illegally poach bongos and other wildlife to supply a much needed source of protein. To learn more about what some groups are doing to help bongos and other so-called "bushmeat" victims, read about the work of the Bushmeat Crisis Task Force (BCTF).

The good news: there are more than 300 mountain bongos in North American zoos. And efforts are underway to use these captive stocks to replenish part of the animals' wild habitat. The Saint Louis Zoo is one of 13 zoos and conservation organizations in the U.S. that has recently sent captive-born mountain bongos to Kenya (see side story). It's hoped that one day the descendants of these animals will once again roam the mountains of East Africa.

Fun Facts

  • Bongos have been known to eat dirt, as well as pieces of burned wood from lightning-killed trees. They apparently do this to obtain salt.
  • The bright chestnut color of the bongo darkens with age. Older animals can be almost black.
  • The common name bongo has nothing to do with drums. It is an African tribal name that probably means antelope.
  • Some native people used to believe that eating or even touching a live bongo would give them spasms similar to epileptic seizures. This taboo once protected the animals, but it is no longer widely held, and bongos are now hunted in great numbers.

Class: Mammalia
Order: Artiodactyla
Family: Bovidae