Okapi (Okapia johnstoni) Fact Sheet: Physical Characteristics

Body measurements

Data sources: Hart (2013)

General

• Medium sized, extremely shy, even-toed ruminant related to giraffes
• Adapted for dense forest living
• Smaller than giraffes, with shorter necks (but necks still longer than most ruminants)
• Okapi backs are nearly level, while giraffe backs slope markedly towards the rear.
• Long skull, large black eyes, large ears
• Teeth show giraffe-like pattern with large gap between incisors and premolars.
  • 32 teeth
  • Enamel is rough or wrinkled, like giraffes'
  • Canine teeth are lobed, as are those of giraffes; lobes most obvious in unworn teeth of calves.
• Large bony capsule enclosing the middle ear bones (auditory bullae), common to many forest-dwelling ruminants (Colbert 1938)
  • These ear bones enhance hearing (plains-dwelling giraffes have much smaller auditory bullae).
  • Can hear and transmit low-frequency sounds below audible range for humans, according to studies in 1992 at the San Diego Zoo and White Oak Conservation Center, Florida. (Lindsey et al 1999)
• Large sinuses in palate
• Muzzle is narrow, nearly pointed, lips mobile and muscular; together with tongue these adaptations well suited to selective feeding on preferred plants.
• Long, prehensile tongue (proportionally longer than the giraffe's).
  • Dark-bluish colored with pointed extremity, smooth base, and papillae on surface.
  • Can be extended 25 cm beyond snout to groom whole body, even wiping the eyes, cleaning the ears and nostrils.
• Skin-covered horn-like ossicones
• Permanent (not shed, like horns)
• Giraffes also have ossicones
• Poor eyesight
• Cervical vertebrae not as elongated as in the giraffe.
• Five sacral (lower back) vertebrae (3-4 in giraffe)
• Only three tarsal (ankle area) bones; giraffes have four tarsal bones.
• Unlike giraffe, okapi has glands between toes on all 4 feet.

Pelage

• Reddish-brown to black, velvety pelage on body and face.
• Black muzzle and nostrils.
• Long, thick eyelashes
• Calf has long hairs around eyes or "false eyelashes" that disappear in time.
• Tapered white or creamy white horizontal stripes on rear and upper front legs
• Anklets and stockings of white on lower legs (perhaps enabling other okapi to easily follow through dark forests as they have poor eyesight).
• Cheeks, throat and rear-most belly are whitish to gray or tan.
• Newborns have similar color and pelage; mane is conspicuous and is largely lost by adulthood
• Hairs of white stripes are longer than hairs in dark stripes

• Males have skin-covered horns
• Females have no horns but do have "bumps" or hair whorls on head where horns would be; occasionally have rudimentary horns.

Genetic characteristics

• Okapis have unusual chromosome numbers; rather the normal 46 chromosomes, numbers may be 45 or even 44 (Lindsey et al 1999)
  • In other animals such variations are abnormal or fatal; okapis with such numbers are otherwise normal.
• Hybrids of okapis with other species not known.

Almost nothing is known about okapi anatomy and physiology.

Note the skin-covered ossicones. These show the okapi is related to giraffes, which also have these permanent horn-like projections.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Bodmer & Rabb (1992)
Colbert (1938)
Dagg & Foster (1982)
Grzimek (1990)
Hart (2013)
Lindsey et al. (1999)