Sunday, 31 October 2010

Okapi

Image of an okapi
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Giraffidae
Genus: Okapia
Species: Okapia johnstoni
Conservation Status: Endangered
Common Name(s): Okapi, African Unicorn, Rainforest Zebra, Atti

The okapi is a beautiful, strange looking giraffid artiodactyl mammal.

Despite what the zebra-like patterns would have you think, the two animals are not closely related. Actually, giraffes are the closest extant relative of O. johnstoni.

Okapis are considered by many scientists to be living fossils,  as they have changed little over their lifetime as a species.

Where do they live?
The species is endemic to the Ituri Rainforest,  in the northeast of the Democratic Republic of Congo, Central Africa.

Okapis are primarily found in altitudes ranging from 500 to 1,000 m, but sometimes individuals venture in higher altitudes, at the eastern montane rainforests. Sightings are most common in the Wamba and Epulu regions.

Discovery
An ancient carved image of the animal discovered in Egypt strongly suggests that the species was known to ancient Egyptians. However, the okapi remained unknown to the Western world until the 20th century. Prior to the animal's official discovery, Henry Morton Stanley (a British journalist and explorer) mentioned in one of his books a donkey-like animal that the natives called the atti. The species was officially described in 1901, using a skull obtained by Sir Harry Johnston, the British governor of Uganda. The story behind the skull is actually a very interesting one.

Supposedly, Johnston witnessed some pygmy Congo inhabitants being abducted by a showman for exhibition. He rescued them and promised to return them to their homes. During this time, the grateful pygmies told Johnston stories about the still unknown animal that Stanley mentioned in his book. With their help, he later managed to acquire pieces of striped skin and the aforementioned skull.

Image showing the distribution of Okapi
Okapi distribution

Description
Okapis have a length of 1.9 to 2.5 meters (head to base of tail), standing 1.5 to 2.0 meters tall at the shoulder. The tail has a length ranging from 30 to 42 centimeters (12 to 17 in.) while their weight can be anywhere from 200 to 300 kg (450 to 650 lb). In captivity, they have a recorded lifespan of over 30 years. In the wild, the average lifespan in the wilderness is unknown.

Heavy raining is quite common in their habitat and as a result they have evolved to have a water resistant, oily and velvety coat of fur, which they develop early on during their childhood.

Image showing the large blue tongue of Okapi
Okapi's large blue tongue

The back is typically reddish or purplish dark and the legs have many horizontal white zebroid-like stripes. Despite of these zebra-resembling markings, the okapi is actually related to giraffes. Most believe that these markings help the younglings follow their mothers through the dense rain forest, while others believe that they are used for camouflage.

Okapis have bodies which are very similar to giraffes, although the neck is shorter. Like giraffes, they have a blue, long and flexible tongue, used for striping leaves and buds from trees and bushes. Their tongue is so long that the okapi can use it to clean its eyelids and ears thoroughly!

The large upright ears help them to detect even the slightest noise, an essential survival trait, that keeps them safe from silent predators like the leopard. Male okapis have two relatively short (6 in. long), skin-covered horns, called ossicones, which develop during the first and fifth year of age.

Both sexes reach sexual maturity at about the age of 2 years old.


Two okapis at Disney's Animal Kingdom
Okapis at Disney's Animal Kingdom


What do okapies eat?
Okapis are herbivorous, eating 18 to 29 kg (40-65 pounds) of food daily. Their diet mainly consists of:
  • Buds
  • Ferns
  • Fruits
  • Fungi
  • Grass
  • Leaves

Fecal examination has concluded that they also eat charcoal from lighting stricken trees and clay. They also have the ability to eat plants which are poisonous and fatal when consumed by humans and other animals.

Predators
The species' main natural predator is the leopard. Leopards can catch both adults and young okapis. When the calf sees a leopard, it will crouch down and lie still. In most cases, the coloration of the okapi will make it invisible to the leopard. A mother may charge an attacking leopard in order to save her calf.


Image of an Okapia johnstoni


Behaviour and Reproduction
Okapis are mostly active during the day, travelling up to half a mile (0.8 km) searching for food, using fixed and well-trodden paths through the jungle. They are solitary animals that come in contact only to breed, with the exception of mothers attending their offsprings. Males are very territorial, trying constantly to keep other males out of their regions, however they do allow female "trespassers" that search for food.


Somba, a Congo Ranger, talks about the okapi in the Okapi Wildlife Reserve, eastern Congo


Breeding behaviours include sniffing, circling and licking each other. When okapis want to find a breeding partner, they utilize their strong and well developed sense of smell.

Females give birth to a single calf , sometime during August to October, after a gestation period of 425 - 492 days (14-15 months). The newborn calf usually weighs 14 to 30 kg (31 - 66 pounds) and is able to stand on its legs for about 30 minutes after being born. The calf will follow its mother around for the next few days until they find a nest. There, the calf remains hidden for the first few weeks. During this period, it won't defecate (they first defecate after 1-2 months) and will only eat very few times. This behavior greatly reduces the chances of a predator sniffing the calves out.

Calves start nursing 1 hour after being born and they wean after about 6 months, although they may continue to suckle for up to a year. The small newborn okapi has the same coloring as adults do, only with the exception of a short fringe of hair located on their spine, which disappears about a month later. Calves triple their weight after only 2 months, and reach adulthood after 2-3 years.


Video of an Okapi calf born at Brookfield Zoo

Generally, mothers are very protective of their young, defending them quite vigorously. They are known to beat their front legs hard on the ground as a warning sign before attacking.

Okapis are silent animals, only making an occasional soft cough during the rut. Calves however, produce a great variety of noises, including:
  • coughs
  • bleats
  • whistles

Image of an okapi from the bristol zoo
Okapi at Bristol Zoo, Bristol, England.

Where can I see one?
Right after their discovery, zoos around the world tried to acquire okapis from the wild. These attempts were accompanied by a high mortality rate, resulting from the rigors and stress of traveling thousands of miles by boat and train. In recent years, shipment by airplane has proven to be a more successful method.

As of today, about 160 okapis are held in zoos and parks all over the world. Most animals are in North American zoos and about 60 individuals in Europe. There are two individuals in South Africa, and seven specimens in Japan. Please note that these numbers may be outdated. Just use google to see if these strange animals are exhibited in a zoo nearby.

From experience, I know you can see two individuals at the London zoo. The videos below were shot in June 2014, when I visited it.


Okapi licking a tree at London zoo


Okapi eating leaves at London zoo


Are they threatened?
The total population of Okapis is estimated to be 10,000 to 35,000 individuals. As of 2013, the animal is listed as endangered. The species is mainly threatened by habitat loss and poaching, both of
which continuously restrict the range of the species and take a heavy toll on their numbers.However, habitat loss due to deforestation as well as poaching continue to restrict the range of the species and take their toll on the pop
On 8 June 2006, researchers reported sightings of surviving okapis in Congo's Virunga National Park. The last known sighting in the park was in 1959. In September 2008, the Wildlife Conservation Society reported that one of their camera traps in Virunga National Park had snapped the first photo of an okapi in the wild.

Some of the efforts that have been made to conserve the species are the following:
  • In the Democratic Republic of Congo there is ongoing conservation work by the Okapi Conservation Project, which includes the continuing study of okapi behavior and lifestyle, which led in 1992 to the creation of the Okapi Wildlife Reserve. During the Congolese Civil War, the reserve was attacked by Congo Rebels. Many animals and workers were killed during the attack.
  • The creation of a captive-breeding center at Epulu, at the heart of the reserve, which is managed jointly by the Congolese Institute for Nature Conservation (ICCN) and Gilman International Conservation. The centre is supported by other organisations including UNESCO, the Frankfurt Zoological Society, the Wildlife Direct and other zoos from all around the world. The Wildlife Conservation Society is also active in the Okapi Wildlife Reserve.


Video about the attack on the Okapi Wildlife Reserve


Quick Interesting facts about okapis
Female okapis are larger than males
They are ruminant animals, just like cows. They swallow and regurgitate their food for some additional chewing. They do this several times, everyday.
- Males urine to mark their territory



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References & Further Reading
- ROGER C. REASON (1991). Preliminary observations on growth and development in the Okapi: Okapia johnstoni at Brookfield Zoo, Chicago International Zoo Yearbook DOI: 10.1111/j.1748-1090.1991.tb03490.x
- Dr. Franz Schwarzenberger, Martina Patzl1, Richard Francke, Andreas Ochs, Rob Buiter, Willem Schaftenaar, Walter De Meurichy (1993). Fecal progestagen evaluations to monitor the estrous cycle and pregnancy in the okapi (Okapia johnstoni) Zoo Biology DOI: 10.1002/zoo.1430120606
- IUCN SSC Antelope Specialist Group (2008). Okapia johnstoni. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 26 November 2013.
- Nowak, Ronald M (1999) Walker's Mammals of the World. 6th ed. p. 1085.

5 comments:

  1. Wow, no one else read this? o_o

    ReplyDelete
  2. can you give me the niche and food web of an okapi? thanx 0.o

    ReplyDelete
  3. i love okapis

    ReplyDelete
  4. They are very unique creatures

    ReplyDelete