The okapi has been the subject of considerable genetic interest ever since chromosome research revealed that individuals having 2n=45 were more common than those having the expected 2n=46. This anomaly has been related to the Robertsian fusion phenomenon (Bodmer 1992).
Perception Channels: tactile ; chemical
The okapi was not recognized by western scientists until 1900, when Harry Johnston sent two pecies of "zebra-like" skin to London (Kingdon 1979). More recently, the okapi has been extirpated from Uganda and, since 1933, protected by law in Zaire. Despite its patchy distribution, the okapi is common in much of its current range and is therefore not listed as a threatened species by international agreement. However, habitat loss due to deforestation as well as poaching continue to restrict the range of the species and take their toll on the population. Another great danger to the okapi is lack of knowledge about it outside of zoos. Little field research has been done on the species due to its inaccessible habitat and reclusive nature (Bodmer 1992).
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: near threatened
Immediately following their discovery in 1900, zoos around the world attempted to obtain okapis from the wild. These initial attempts were accompanied by a high mortality rate due to the rigors of traveling thousands of miles by boat and by train. In more recent years, shipment by airplane has proven more successful. Today, many zoos keep and breed okapis, and many people visit these zoos each year to see them (Grzimek 1990).
Okapis are diurnal and forage along fixed, well-trodden paths through the forest (Grzimek 1990). They feed primarily on the leaves, buds, and shoots of more than 100 different species of forest vegetation (Bodmer 1992). Many of the plant species fed upon by the okapi are known to be poisonous to humans. Additionally, okapis eat grasses, fruits, ferns, and fungi. Examination of okapi feces has revealed that the charcoal from trees burnt by lightning is consumed as well. Field observations indicate that the okapi's mineral and salt requirements are filled primarily by a sulfurous, slightly salty, reddish clay found near rivers and streams (Grzimek 1990).
Okapis are found only in the tropical forests of northeastern Zaire. They prefer altitudes between 500 and 1,000 m, although they may venture above 1,000 m in the eastern montane rainforests. One sighting occurred at 1,450 m on Mt. Hoyo, in the upper Ituri. The range of the okapi is limited by high montane forests to the east, swamp forests below 500 m to the west, savannas of the Sahel/Soudan to the north, and open woodlands to the south. Okapis are most common in the Wamba and Epulu areas (Bodmer 1992).
Biogeographic Regions: ethiopian (Native )
Okapis occur in the dense rainforests at middle elevations within their range. They frequent river banks and stream beds and may occasionally venture into areas of secondary forest growth (Bodmer 1992).
Terrestrial Biomes: rainforest
Average lifespan
Status: captivity: 30.0 years.
Average lifespan
Status: captivity: 15.0 years.
Average lifespan
Status: captivity: 33.0 years.
The okapi has a form superficially resembling that of a horse. Average body length is 2.5 m, and average height at the shoulder is 1.5 m. The neck is relatively long in comparison to that of other ruminants, and the ears are large and flexible. The body is chocolate-brown, with creamy white horizontal stripes on the legs and hindquarters and white stockings on the ankles. The cheeks, throat, and chest are whitish-gray or tan (Bodmer 1992). The unique color pattern of the okapi allows it to disappear into the background of dense vegetation and rotting leaves where it lives (Grzimek 1990). Male okapis have hair-covered horns not exceeding 15 cm in length. The horns are fused to the frontal bones over the orbits and project rearward. Females may be slightly red in color, lack horns, and average 4.2 cm taller than males. Both males and females have interdigital glands on the front and hind feet (Bodmer 1992). The most giraffe-like feature of the okapi is the long black tongue which is used for plucking buds, leaves, and branches from trees and shrubs as well as for grooming (Kingdon 1979). In addition, the walking gait of the okapi closely resembles that of a giraffe. Both giraffe and okapi simultaneously step with the front and hind leg on the same side of the body rather than moving alternate legs on either side like other ungulates (Dagg, 1960).
Range mass: 200 to 300 kg.
Other Physical Features: endothermic ; bilateral symmetry
In the wild, okapis are solitary, coming together primarily for mating. Okapi courtship and mating rituals are known only from observations done in zoos. Partners begin courtship by circling, sniffing, and licking eachother. Eventually, the male asserts his dominance by extending his neck, tossing his head, and thrusting one leg foreward. This display is followed by mounting and copulation. After mating, the male and female part (Grzimek 1990). The gestatation period lasts about 440 days (Bodmer 1992), and females retreat into dense forest vegetation to give birth (Grzimek 1990). Newborn okapis weigh 14-30 kg at birth. They are precocial and may nurse after 21 minutes and stand after just 30 minutes. Young spend the first day or two of life following the mother around and exploring the environment. After this, they find a suitable hiding spot and make a nest. For the next two months, they spend 80% of their time in this nest. Hiding behavior appears to promote rapid growth and provides protection from predators. A disturbed calf lies motionless in its nest, and a female okapi will rush to aggressively defend her calf from danger. During the hiding stage, young nurse relatively infrequently and do not defecate. These strategies help keep them undetected by predators. Weaning occcurrs at about 6 months, although young may continue to suckle for more than a year. Young males begin developing horns at one year of age, and both males and females reach adult size at about three years. In captivity, the youngest female to breed was 1 year 7 months old, and the youngest male was 2 years 2 months old. The okapi's lifespan is about 30 years in captivity, but data from wild populations is unavailable (Bodmer 1992).
Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 16000 g.
Average gestation period: 458 days.
Average number of offspring: 1.
Average age at sexual or reproductive maturity (male)
Sex: male: 790 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 578 days.
