Okapi

About the okapi

The okapi is endemic to the northeast Democratic Republic of the Congo, though non-invasive genetic testing suggests a population may also live southwest of the Congo River. Its zebra-like leg stripes make it a strange animal to place at first glance, but it isn't related to zebras at all — it's most closely related to the giraffe, and the two species are the only living members of the family Giraffidae. For years, Europeans in Africa had only rumors of an animal they called the African unicorn, until British commissioner Sir Harry Johnston obtained a striped skin and a skull in the Ituri Forest; from that skull, the okapi was correctly placed among the giraffids, and the species was formally described in 1901 as Okapia johnstoni.

An okapi stands about 1.5 m (4 ft 11 in) at the shoulder with a body length around 2.5 m (8 ft 2 in) and weighs 200 to 350 kg (440 to 770 lb). It has a long neck and large, flexible ears. The coat is chocolate to reddish brown, broken up by white horizontal stripes and rings on the legs and white ankles — camouflage that works well in dense forest. The face, throat, and chest are greyish white. Males carry short, hair-covered, horn-like structures called ossicones, under 15 cm (5.9 in) long; females lack them, growing hair whorls in their place instead, and stand about 4.2 cm (1.7 in) taller on average with a slightly redder coat. Both sexes have a long, black tongue — longer than a giraffe's — used for plucking leaves and buds as well as for grooming, and both walk with the same pacing gait as giraffes, moving the front and hind leg on one side of the body together rather than alternating sides.

Okapis inhabit canopy forest at elevations of 500 to 1,500 m (1,600–4,900 ft) within the Ituri rainforest and surrounding river basins. Genetically, the species diverged from a common ancestor with the giraffe roughly 11.5 million years ago, and its resemblance to older, more primitive giraffids has led some to call it a living fossil.

Behavior and diet

Okapis are mostly active during the day, though they may move around for a few hours after dark. They are essentially solitary, coming together only to breed, and live at low densities — around 0.6 animals per km² across overlapping home ranges. Male ranges average 13 km² (5.0 sq mi), considerably larger than the 3–5 km² (1.2–1.9 sq mi) held by females; males roam continuously while females stay put, and males mark territory and bushes with urine while females use shared defecation sites. Okapis groom themselves and each other, focusing on the earlobes and neck, and often rub their necks against trees, leaving a brown residue behind. A male tolerates females passing through his territory to forage and visits their ranges at breeding time. Generally calm, an okapi will kick or head-butt to show aggression, and with poorly developed vocal cords, it's mostly limited to three sounds: a contact "chuff" from either sex, a courtship "moan" from females, and a stress "bleat" from infants. The leopard is its main natural predator.

An okapi is a herbivore that browses on tree leaves and buds, branches, grasses, ferns, fruits, and fungi, feeding on more than 100 plant species, some of which are toxic to humans and other animals. It is the only known mammal in the Ituri Forest that feeds solely on understory vegetation, reaching it with an 18-inch (46 cm) tongue, and it prefers to feed in gaps left by fallen trees. No single plant dominates its diet; woody, dicot species make up the bulk of it, while monocots are eaten rarely.

Females mature sexually at about a year and a half, males at two years, and breeding doesn't depend on season — captive females cycle into estrus every 15 days. Courtship involves circling, smelling, and licking before mounting. Gestation runs 440 to 450 days and typically produces a single calf weighing 14 to 30 kg (31–66 lb). The mother eats the afterbirth and grooms the calf extensively; her milk is rich in protein and low in fat. A newborn can stand within 30 minutes and, notably, doesn't defecate for its first month or two of life, likely a way of avoiding detection by predators while at its most vulnerable. Calves start on solid food at three months and are weaned at six; males grow their ossicones over their first year. A typical okapi lives 20 to 30 years.

Range and habitat

The okapi is endemic to the Democratic Republic of the Congo, occurring north and east of the Congo River from Maiko National Park northward through the Ituri rainforest and the river basins of the Rubi, Lake Tele, and Ebola, up to the Ubangi River. Smaller populations exist west and south of the river as well, and genetic evidence suggests the species also occurs southwest of the Congo River. It is common around Wamba and Epulu but is now extinct in Uganda, where evidence suggests it once lived in the Semuliki Valley until disappearing in the late 1970s.

The species inhabits canopy forest at elevations of 500 to 1,500 m (1,600–4,900 ft), occasionally using seasonally flooded areas but avoiding gallery forest, swamp forest, and land disturbed by human settlement. In the wet season, okapis visit rocky inselbergs that offer forage not found elsewhere in the forest. A study in a mixed Cynometra forest in the late 1980s recorded an average population density of 0.53 animals per km².

Conservation status

The okapi is classified as Endangered on the IUCN Red List and is fully protected under Congolese law. Significant populations persist in the Okapi Wildlife Reserve and Maiko National Park, with smaller numbers in the Rubi Tele Hunting Reserve, the Abumombanzi Reserve, the Sankuru Nature Reserve, and Lomami National Park, but numbers have been in steady decline. The main threats are habitat loss from logging and human settlement, hunting for bushmeat and skin, and illegal mining. A more recent threat is the presence of illegal armed groups around protected areas, which has blocked conservation and monitoring work — a small population north of Virunga National Park currently goes unprotected for this reason. The Okapi Conservation Project, established in 1987, works to protect okapi populations in the wild.