Okapi

## It's related to giraffes?!

The okapi (pronounced oh-COP-ee) is a beautiful and unusual animal. With its white-and-black striped hindquarters and front legs, it looks like it must be related to zebras! But take a look at an okapi’s head, and you’ll notice a resemblance to giraffes. The okapi is indeed the only living relative of the giraffe. Like a giraffe, the okapi has very large, upright ears, which catch even slight sounds, helping the animal avoid trouble. The okapi also has a long, dark, prehensile tongue, just like a giraffe’s, to help it strip the buds and young leaves from the understory brush of its rain forest home.

## Call me bashful

Okapis are hard to find in the wild. Their natural habitat is the Ituri Forest, a dense rain forest in central Africa. Okapis are very wary, and their highly developed hearing alerts them to run when they hear humans in the distance. In fact, while natives of the Ituri Forest knew of okapis and would occasionally catch one in their pit traps, scientists did not know of the animal until 1900. The secretive nature of okapis and the difficulty most humans have of traveling in their habitat have made okapis hard to observe in the wild. Therefore, researchers can only estimate how many okapis live there. It is believed that there are currently about 25,000 okapis in the wild.

## Made for a rain forest

Why does the okapi have zebra-like stripes? These markings, which seem very bold to us, give the animal great camouflage when hiding in the partial sunlight that filters through the dense rain forest. The stripes may also help a young okapi follow its mother through the dark forest, and they may help adults find each other, too. The okapi’s dark purplish or reddish-brown fur is dense and feels like velvet. It’s also oily, so water slides right off, keeping the okapi dry on rainy days. Only the males have horns, which are covered by skin and are short and slant backwards, so they won’t get tangled in forest branches.

If okapis are related to giraffes, why aren’t they as tall as giraffes? In a rain forest, there are trees with branches hanging down, as well as roots and tree trunks to dodge. Okapis need to have shorter legs and necks to help them swerve around these obstacles. Being really tall is not a good idea in a forest!

## Hide and seek

Okapis often travel up to 0.5 miles (0.8 kilometers) a day in search of food, usually along trails worn down by generations of okapis. They are generally solitary animals, unless an adult female has a calf with her. Adult males have home ranges that cover more area, and they can travel up to 2.5 miles (4 kilometers) a day. The males try to keep other males out of their territories but allow females to travel through in search of food.

## Leafy buffet

Both male and female okapis are most active during the afternoon through the evening. They are important forest browsers, eating 40 to 65 pounds (18 to 29 kilograms) of leaves, twigs, and fruits each day and leaving a "pruning line" in the foliage. Okapis use their prehensile tongue to get food by pulling leaves from trees and into their mouth. The tongue is also an important grooming tool, helping to keep the velvety soft, short coat in tip-top shape. Okapis have also been seen eating clay and burnt charcoal, probably for minerals. And just like giraffes, sheep, and goats, okapis are ruminants.

At the San Diego Zoo and the San Diego Zoo Safari Park, okapis are fed alfalfa hay and pellets, leafy acacia branches, carrots, and yams.

## Dodging danger

Okapis are very shy animals. Their reddish brown-black coat camouflages them in the deep forest. In the thick trees and underbrush, okapis rely on their hearing to warn them of danger. Their huge ears pick up even the softest sounds coming from any direction. They listen for leopards, which hunt adult okapis, as well as smaller wild cats, which can attack a young calf.

## I smell you

While okapis travel for the most part by themselves within their home ranges, they still have ways of communicating with others whose ranges overlap. A scent gland on each foot leaves behind a sticky, tar-like substance wherever they have walked, marking their territory. Okapis have a great sense of smell. By checking the ground, an okapi can tell if another okapi has been there. Males also mark their territory by urine spraying. Normally silent, female okapis vocalize only when they are ready to breed.

## I heard it through the grapevine

In 2008, San Diego Zoo researchers discovered that okapis have a secret language. They watched okapis closely and recorded their sounds. The researchers heard coughs, bleats, and whistles quite often, but it wasn’t until they returned to the Sensory Ecology Lab to examine their recordings closely that they realized okapis also use other calls with very low frequencies. These calls are so low, in fact, that we humans cannot hear them at all! It’s only when we look at recordings via specialized computer software that these infrasonic mutterings become visible.

Our researchers then recorded our okapis around the clock to find out why they use these low-pitched calls. One explanation is that these calls have evolved for communication between Mom and her baby while she’s out foraging. In this situation, Mom can “check in” with her offspring without alerting potential predators of the fact that her baby is vulnerable. Predators remain unaware of these chats, as, like us, they cannot hear sounds so low in pitch. It’s the okapi version of students who text message each other in class so that the teacher is unaware that they are “talking.”

## Calf care

Okapi newborns can stand up within 30 minutes of birth and nurse for the first time within an hour of birth. They have the same coloring as an adult but have a short fringe of hair along the spine, which generally disappears by the time they are 12 to 14 months old. In the wild, mothers hide their newborn calves in one spot, returning regularly to allow the calf to nurse.

An okapi calf starts trying solid food at just three weeks old and defecates (poops) for the first time between four and eight weeks of age. This adaptation helps keep predators from sniffing out the hidden newborns until they have had a chance to grow and gain strength. Calves triple their size by the end of their second month but do not reach full adult size until three years of age.