Tragelaphus eurycerus isaaci

About the Bongo


Geographic Range:


Class: Mammalia
Order: Cetartiodactyla
Family: Bovidae
Genus: Tragelaphus
Species: eurycerus
Subspecies: isaaci

Once called “ghosts of the forest,” bongos are known for being almost silent as they move through dense forests of Africa. Bongos weren't discovered by modern biologists until the middle of the last century. Bongos are among the largest of African antelope, and they're recognized by their chestnut-red color and thin white stripes. Males and females are similar in appearance, but males are larger and their coats darken with age. Both sexes have horns; males' horns grow longer and thicker.

Bongo Facts

The bongo is a large antelope with short legs and a heavy build. They’re chestnut brown in color with vertical white stripes running down their flank. These stripes break up their outline in the forest, and they may also serve as a means for herds to identify one another.

Both sexes have spiraling horns, although female horns are shorter, thinner and more parallel than those of males. Bongos are the only spiral-horned antelopes with horned males and females, and they're among the largest of African antelope. They have relatively shorter legs than plains antelope, allowing them to traverse the dense underbrush quickly. Their large ears are able to pick up sounds in their dark habitats.

The bongo has a prehensile tongue, which helps it reach high vegetation or pull roots from the ground. Like other antelopes and cattle (which they're related to), bongos have four-chambered ruminating stomaches to help break down plant cellulose.

Up to 4.3 feet at the shoulder; generally between 450 to 800 pounds.

In the wild, bongos eat leaves, grasses and shoots. They supplement their diet with naturally occurring salt deposits.

Mating occurs seasonally, but patterns are not yet understood. Females come into estrus every 21-22 days, remaining in this state for three days. A single calf is born after a nine-month gestation period. To protect her vulnerable calf from predators, the female gives birth in dense vegetation and leaves the baby lying silently for about a week. She'll reguarly return to nurse, and when the calf is strong enough, they re-join other females and their young for better protection.

Calves grow relatively quickly, and their horns appear around three to four months of age. Weaning occurs at six months, but calves tend to remain longer with the nursery group. Sexual maturity is reached after 1.5 to 2.5 years.

Bongos are highly reclusive. Most behavioral information has been taken from captive individuals or from rare encounters in the wild. They tend to be crepuscular, meaning they’re most active near dusk or dawn. When bongos sense danger, they turn their backs to danger, as this makes them less noticeable due to their striped behinds. They’ll continue to turn back to assess the threat, darting into the brush if necessary.

Bongos produce a variety of different calls to communicate danger or distress, including grunts, snorts and squeals.

Females form small herds of fewer than nine individuals, and males leave their maternal herd once they reach adulthood. Males remain solitary until it’s time to mate. They typically avoid other males, though they’ve been known to challenge one another.

Role in their habitat:
Bongos are browsers that stimulate new growth. They’re preyed upon by leopards and humans.

The bongo is found in dense mountainous forests in East Africa.

Median Life Expectancy:
Males: 9.2 years

Females: 12.3 years

Eastern/Mountain bongo subspecies are critically endangered. Western/Lowland bongo subspecies are near threatened. Their numbers are declining due to habitat destruction and hunting. Captive populations are faring much better, and the population in the U.S. alone exceeds their population in the wild.

Fun Facts

  • Despite their large horns, bongos can move very quickly. While running, they will tilt their chin up so their horns lie flat against their back. Bongos have been known to rub bald spots on their backs with the tips of their horns.
  • The bright chestnut color of the bongo darkens with age. Older animals can be almost black.