Form and Function

The okapi are a four-legged mammal that is closely related to the giraffe. Physically they look strange compared to other animals in the area. Its body is a brownish-red color from the legs up. Its legs are white with black stripes, similar to that of a zebra. Normally the hairs on the white stripes are longer than those on the dark stripes (Quenqua, 2011). The hair on an okapi’s muzzle is black that fades to white as it approaches the jawline and continues down to the neck. Its coat is velvety and helps repel water (Quenqua, 2011).

Giraffes are the closest relative to the okapi and these two have many similarities. Their backs are both sloped so that their forequarters are elevated higher than their rear and because of this the okapi must splay its legs to the side in order to drink similarly to the giraffe. (Lindsey, 1956). The okapi and giraffe have even toed feet with glands between them (Lindsey, 1956). However, unlike giraffes they have three tarsal bones instead of four (Lindsey 1956). They also have a shorter neck than giraffes but longer ones than most other ruminants such as the domestic cow and the white-tailed deer.

Unlike many mammals the okapi does not usually have 36 chromosomes. Although some do, the majority of the okapi have 35 or even 34 chromosomes instead (Lindsey, 1956). This has been related to the Robertson fusion phenomenon (Bodmer and Rabb, 1992). The Robertson fusion can result in two things. One is that two centromeres fuse into one and the other is when one centromere splits into two (Veith, 2009). In some species this can cause mental problems such as down and patau syndrome (Veith, 2009). This does not seem to cause and physical or mental problems in the okapi though.

Some of the okapi’s senses are more prominent than others. Their large ears and auditory bullae enhance the okapi’s hearing. The auditory bullae is a large bony capsule enclosing the middle ear bones (Lindsey, 1956). Despite their large eyes, the okapi have a poor vision. The okapi’s muzzle is narrow and strong to help with feeding. Okapi have 32 teeth with wrinkled enamel and a large gap between incisors and premolars (Colbert, 1938). Similar to giraffes they have lobed canine teeth. It also has a long dark blue tongue that can stretch up to 25 cm (Dagg, 1960).  This not only is a benefit for feeding but also for cleanliness. They use their tongue to clean both their eyes and ears.  

Male and female okapi look similar but have some physical differences. The average height of an okapi is around 5 feet tall. Female okapi tend to be taller than their male counterparts, usually by 2 inches. (Bodmer and Rabb, 1992). Both male and female okapi are about 2.5 meters (8 feet) long (Bodmer and Rabb, 1992). Though the females are taller they weigh significantly less than males. The average female weighs between 55 and 100 pounds while the male okapi can be four times heavier, ranging from 441 to 641 pounds (Bodmer and Rabb, 1992). Another difference between male and female okapi is horns. Female okapi lack horns but do have small bumps on their head where the horns on male okapi are located (Bodmer an Rabb, 1992). Horns on a male are covered with a thin layer of skin. The horns can extend up to but no greater than 15 cm.

The life expectancy of the okapi is anywhere between 15 and 20 years for those who survive their first year (Bodmer and Rabb, 1992). Infant okapi weigh 14-30 kg at birth and are able to stand on their own only a half hour after birth (Bodmer and Rabb, 1992). Their weight will approximately double within the first month. They start developing their horns after one year and reach adult size in approximately 3 years (Lindsey, 1956). Sexual maturity is reached earlier than this but it differs between males and females. Females reach sexual maturity faster than males. They take about 1 year and 7 months where males take 2 years and 2 months to reach sexual maturity (Bodmer and Rabb, 1992). Baby okapi do not defecate during the first month of their life. This helps prevent predators from picking up their scent (Quenqua, 2011).

The okapi are unique creatures. Though similar to giraffes they have several physical differences like their chromosome number. Along with differences between species there are also several between the male and females. Overall this is a strange and rare creature that is interesting to learn about.