The okapi, often referred to as the “forest giraffe,” is an elusive mammal found primarily in the dense rainforests of the Democratic Republic of Congo. The only living relative of the giraffe, it possesses a striking appearance with a dark, velvety coat and distinctive white horizontal stripes on its hindquarters and front legs. These markings provide effective camouflage within the dappled light of its forest habitat. Okapis also have specialized headgear.
Understanding Okapi Ossicones
Okapis have specialized structures called ossicones, not horns. These bony, permanent protuberances are covered in skin and fur, and found exclusively on male okapis. Unlike true horns, which consist of a bony core covered by a keratin sheath and are never shed, ossicones develop differently. They also differ from antlers, which are entirely bone, branched, and shed and regrown annually.
Ossicones are unique to the Giraffidae family, which includes both okapis and giraffes. While both male and female giraffes possess ossicones, only male okapis develop them. Female okapis have small bumps or hair whorls in their place, highlighting a clear sexual dimorphism within the species.
Appearance and Growth
Okapi ossicones are conical and can reach 10 to 15 centimeters (4 to 6 inches) above the skull. They are covered with soft, fur-covered skin, making them feel less rigid than a typical horn. The hair on the tips of these ossicones may become rubbed away, exposing the bone, particularly in older males.
These structures do not appear at birth. Instead, they begin as cartilaginous knobs, which gradually ossify, or turn into bone, as the male okapi matures. Ossicone development starts around one year of age and they fuse to the skull between one and five years of age. This process results in permanent headgear that remains throughout the animal’s life.
Purpose and Role
The ossicones of male okapis serve several functions, primarily related to social interactions and display. They play a role in establishing dominance hierarchies among males within their solitary social structure. Males may use their heads in combat, where the ossicones add weight and concentrate impact, similar to how giraffes use their ossicones during “necking” to deliver blows.
Ossicones also act as a visual display for attracting mates, signaling the male’s maturity and strength to potential partners. While they can be used for defense against predators or rivals, their relatively small size and skin covering mean their effectiveness in direct combat is more limited compared to animals with large, keratinous horns or robust antlers. Some researchers also consider a possible role in thermoregulation, due to the presence of nerve bundles and a rich blood supply within ossicones.