dcsimg

Lifespan, longevity, and ageing

provided by AnAge articles
Maximum longevity: 33.5 years (captivity)
license
cc-by-3.0
copyright
Joao Pedro de Magalhaes
editor
de Magalhaes, J. P.
partner site
AnAge articles

Morphology

provided by Animal Diversity Web

The okapi has a form superficially resembling that of a horse. Average body length is 2.5 m, and average height at the shoulder is 1.5 m. The neck is relatively long in comparison to that of other ruminants, and the ears are large and flexible. The body is chocolate-brown, with creamy white horizontal stripes on the legs and hindquarters and white stockings on the ankles. The cheeks, throat, and chest are whitish-gray or tan (Bodmer 1992). The unique color pattern of the okapi allows it to disappear into the background of dense vegetation and rotting leaves where it lives (Grzimek 1990). Male okapis have hair-covered horns not exceeding 15 cm in length. The horns are fused to the frontal bones over the orbits and project rearward. Females may be slightly red in color, lack horns, and average 4.2 cm taller than males. Both males and females have interdigital glands on the front and hind feet (Bodmer 1992). The most giraffe-like feature of the okapi is the long black tongue which is used for plucking buds, leaves, and branches from trees and shrubs as well as for grooming (Kingdon 1979). In addition, the walking gait of the okapi closely resembles that of a giraffe. Both giraffe and okapi simultaneously step with the front and hind leg on the same side of the body rather than moving alternate legs on either side like other ungulates (Dagg, 1960).

Range mass: 200 to 300 kg.

Other Physical Features: endothermic ; bilateral symmetry

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Palkovacs, E. 2000. "Okapia johnstoni" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Okapia_johnstoni.html
author
Eric Palkovacs, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web

Life Expectancy

provided by Animal Diversity Web

Average lifespan
Status: captivity:
30.0 years.

Average lifespan
Status: captivity:
15.0 years.

Average lifespan
Status: captivity:
33.0 years.

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Palkovacs, E. 2000. "Okapia johnstoni" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Okapia_johnstoni.html
author
Eric Palkovacs, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web

Habitat

provided by Animal Diversity Web

Okapis occur in the dense rainforests at middle elevations within their range. They frequent river banks and stream beds and may occasionally venture into areas of secondary forest growth (Bodmer 1992).

Terrestrial Biomes: rainforest

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Palkovacs, E. 2000. "Okapia johnstoni" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Okapia_johnstoni.html
author
Eric Palkovacs, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web

Distribution

provided by Animal Diversity Web

Okapis are found only in the tropical forests of northeastern Zaire. They prefer altitudes between 500 and 1,000 m, although they may venture above 1,000 m in the eastern montane rainforests. One sighting occurred at 1,450 m on Mt. Hoyo, in the upper Ituri. The range of the okapi is limited by high montane forests to the east, swamp forests below 500 m to the west, savannas of the Sahel/Soudan to the north, and open woodlands to the south. Okapis are most common in the Wamba and Epulu areas (Bodmer 1992).

Biogeographic Regions: ethiopian (Native )

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Palkovacs, E. 2000. "Okapia johnstoni" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Okapia_johnstoni.html
author
Eric Palkovacs, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web

Trophic Strategy

provided by Animal Diversity Web

Okapis are diurnal and forage along fixed, well-trodden paths through the forest (Grzimek 1990). They feed primarily on the leaves, buds, and shoots of more than 100 different species of forest vegetation (Bodmer 1992). Many of the plant species fed upon by the okapi are known to be poisonous to humans. Additionally, okapis eat grasses, fruits, ferns, and fungi. Examination of okapi feces has revealed that the charcoal from trees burnt by lightning is consumed as well. Field observations indicate that the okapi's mineral and salt requirements are filled primarily by a sulfurous, slightly salty, reddish clay found near rivers and streams (Grzimek 1990).

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Palkovacs, E. 2000. "Okapia johnstoni" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Okapia_johnstoni.html
author
Eric Palkovacs, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web

Benefits

provided by Animal Diversity Web

Immediately following their discovery in 1900, zoos around the world attempted to obtain okapis from the wild. These initial attempts were accompanied by a high mortality rate due to the rigors of traveling thousands of miles by boat and by train. In more recent years, shipment by airplane has proven more successful. Today, many zoos keep and breed okapis, and many people visit these zoos each year to see them (Grzimek 1990).

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Palkovacs, E. 2000. "Okapia johnstoni" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Okapia_johnstoni.html
author
Eric Palkovacs, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web

Untitled

provided by Animal Diversity Web

The okapi has been the subject of considerable genetic interest ever since chromosome research revealed that individuals having 2n=45 were more common than those having the expected 2n=46. This anomaly has been related to the Robertsian fusion phenomenon (Bodmer 1992).

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Palkovacs, E. 2000. "Okapia johnstoni" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Okapia_johnstoni.html
author
Eric Palkovacs, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web

Behavior

provided by Animal Diversity Web

Perception Channels: tactile ; chemical

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Palkovacs, E. 2000. "Okapia johnstoni" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Okapia_johnstoni.html
author
Eric Palkovacs, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web

Conservation Status

provided by Animal Diversity Web

The okapi was not recognized by western scientists until 1900, when Harry Johnston sent two pecies of "zebra-like" skin to London (Kingdon 1979). More recently, the okapi has been extirpated from Uganda and, since 1933, protected by law in Zaire. Despite its patchy distribution, the okapi is common in much of its current range and is therefore not listed as a threatened species by international agreement. However, habitat loss due to deforestation as well as poaching continue to restrict the range of the species and take their toll on the population. Another great danger to the okapi is lack of knowledge about it outside of zoos. Little field research has been done on the species due to its inaccessible habitat and reclusive nature (Bodmer 1992).

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: near threatened

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Palkovacs, E. 2000. "Okapia johnstoni" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Okapia_johnstoni.html
author
Eric Palkovacs, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web

Reproduction

provided by Animal Diversity Web

In the wild, okapis are solitary, coming together primarily for mating. Okapi courtship and mating rituals are known only from observations done in zoos. Partners begin courtship by circling, sniffing, and licking eachother. Eventually, the male asserts his dominance by extending his neck, tossing his head, and thrusting one leg foreward. This display is followed by mounting and copulation. After mating, the male and female part (Grzimek 1990). The gestatation period lasts about 440 days (Bodmer 1992), and females retreat into dense forest vegetation to give birth (Grzimek 1990). Newborn okapis weigh 14-30 kg at birth. They are precocial and may nurse after 21 minutes and stand after just 30 minutes. Young spend the first day or two of life following the mother around and exploring the environment. After this, they find a suitable hiding spot and make a nest. For the next two months, they spend 80% of their time in this nest. Hiding behavior appears to promote rapid growth and provides protection from predators. A disturbed calf lies motionless in its nest, and a female okapi will rush to aggressively defend her calf from danger. During the hiding stage, young nurse relatively infrequently and do not defecate. These strategies help keep them undetected by predators. Weaning occcurrs at about 6 months, although young may continue to suckle for more than a year. Young males begin developing horns at one year of age, and both males and females reach adult size at about three years. In captivity, the youngest female to breed was 1 year 7 months old, and the youngest male was 2 years 2 months old. The okapi's lifespan is about 30 years in captivity, but data from wild populations is unavailable (Bodmer 1992).

Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous

Average birth mass: 16000 g.

Average gestation period: 458 days.

Average number of offspring: 1.

Average age at sexual or reproductive maturity (male)
Sex: male:
790 days.

Average age at sexual or reproductive maturity (female)
Sex: female:
578 days.

license
cc-by-nc-sa-3.0
copyright
The Regents of the University of Michigan and its licensors
bibliographic citation
Palkovacs, E. 2000. "Okapia johnstoni" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Okapia_johnstoni.html
author
Eric Palkovacs, University of Michigan-Ann Arbor
original
visit source
partner site
Animal Diversity Web

Biology

provided by Arkive
Most of the information about the biology of the okapi is from captive animals (2). They are largely solitary (2) and though once thought to be nocturnal (6), are now known to be active during the day (2). They feed largely on leaves, grasses, fruits and fungi, some of which are known to be poisonous. It has been suggested that this is why okapis eat charcoal from burned forest trees, as is evidenced from their dung (2). Carbon, in the form of charcoal, is an excellent antidote for toxin ingestion and recent observations in Zanzibar found red colobus monkeys eating charcoal from native cooking fires and kilns (7). It is also known that many other animals find sources of kaolin, a type of clay, to offset the effects of poisonous leaves and fruit in their diet. Male and female okapi live in home ranges, but they are not territorial and these ranges overlap (3). From observations on captive animals, it appears that male okapis mark their ranges with urine, by crossing their front legs, urinating on them, and then walking through their range. They will also urinate directly onto plants. Both males and females rub their necks against tree trunks (3). Mothers will not stray very far after giving birth, so the young okapi will remain close by until at least a few days old, in what is known as a 'follower phase' (3). It then becomes a 'nester' for a number of months, in which it lies in vegetation. During this intensive nesting phase, the calf is extremely efficient in the use of energy, primarily only nursing or sleeping. Towards the end of the intensive nesting phase, the calf can maintain its temperature properly, and so activates its rumens, and defecates for the first time (3). This is thought to be a defence against predators (2). Okapi mothers use infrasonic communication to communicate with their calves. This is sound that is below the range of human hearing – also used by elephants (3). The young are weaned at six months old although they may continue to take milk for some time afterwards. The males begin developing their horns at about one year and reach their adult size at the age of three. They are believed to reach sexual maturity around two years old (2). Captive individuals have been known to live for up to 33 years (3).
license
cc-by-nc-sa-3.0
copyright
Wildscreen
original
visit source
partner site
Arkive

Conservation

provided by Arkive
The okapi is classified as Lower Risk - near threatened by the World Conservation Union (IUCN) Red List of Threatened Species. Its populations are thought to be stable at the present time (1). However, with increased deforestation to provide agricultural areas to feed an increasing human population within the animal's range, more studies of the wild okapi may be needed to accurately assess its conservation requirements (2).
license
cc-by-nc-sa-3.0
copyright
Wildscreen
original
visit source
partner site
Arkive

Description

provided by Arkive
Perhaps the most extraordinary fact about the okapi is that it was not known to science until 1901 (4). Its taxonomic name, Okapia johnstoni, honours both its native Central African name (5), and that of the man who first 'discovered' it, Sir Harry Johnston, the British explorer, naturalist and colonial administrator (4). The native pygmies of Central Africa had known of this animal's existence for generations, thinking it was a type of horse, which was how they described it to Sir Henry Morton Stanley (of 'Dr. Livingstone, I presume' fame) (4). In fact, the okapi is a forest-living relative of the giraffe (4). Although closely resembling a horse, the okapi has a relatively long neck although not as long as its giraffe cousins. The forehead, neck and body are brown, with light tan or grey on the animal's cheeks, throat and chest. Okapi hair is short, slightly oily to the touch and has a delicate scent (3). The hind limbs and upper forelegs have cross-stripes resembling those of a zebra whilst the lower limbs have white 'socks' with brown lines running up the front to the knees, where there is a brown band circling each leg (3). Males have short hair-covered, rearward-facing horns and both sexes have large mobile ears. Females are slightly taller than males (2).
license
cc-by-nc-sa-3.0
copyright
Wildscreen
original
visit source
partner site
Arkive

Habitat

provided by Arkive
Okapis are forest animals, found in both dry and rain forest in tropical and sub-tropical latitudes (1) (2).
license
cc-by-nc-sa-3.0
copyright
Wildscreen
original
visit source
partner site
Arkive

Range

provided by Arkive
The okapi is found in the Democratic Republic of Congo and in the forested regions of Uganda (1).
license
cc-by-nc-sa-3.0
copyright
Wildscreen
original
visit source
partner site
Arkive

Status

provided by Arkive
Classified as Lower Risk - near threatened (LR/nt) on the IUCN Red List 2003 (1)
license
cc-by-nc-sa-3.0
copyright
Wildscreen
original
visit source
partner site
Arkive

Threats

provided by Arkive
The main threat to the okapi is loss of its habitat to agriculture and encroaching human settlements. Hunting is also a problem in some regions (1).
license
cc-by-nc-sa-3.0
copyright
Wildscreen
original
visit source
partner site
Arkive

Size

provided by EOL authors
Body Length: 200-210 cm / 6.6-7 ft.
Shoulder Height: 150-170 cm / 5-5.6 ft.
Tail Length: 30-42 cm / 12-16.8 in.
Weight: 210-250 kg / 462-550 lb.

Okapi

provided by wikipedia EN

The okapi (/ˈkɑːp/; Okapia johnstoni), also known as the forest giraffe, Congolese giraffe and zebra giraffe, is an artiodactyl mammal that is endemic to the northeast Democratic Republic of the Congo in central Africa. It is the only species in the genus Okapia. Although the okapi has striped markings reminiscent of zebras, it is most closely related to the giraffe. The okapi and the giraffe are the only living members of the family Giraffidae.

The okapi stands about 1.5 m (4 ft 11 in) tall at the shoulder and has a typical body length around 2.5 m (8 ft 2 in). Its weight ranges from 200 to 350 kg (440 to 770 lb). It has a long neck, and large, flexible ears. Its coat is a chocolate to reddish brown, much in contrast with the white horizontal stripes and rings on the legs, and white ankles. Male okapis have short, distinct horn-like protuberances on their heads called ossicones, less than 15 cm (5.9 in) in length. Females possess hair whorls, and ossicones are absent.

Okapis are primarily diurnal, but may be active for a few hours in darkness. They are essentially solitary, coming together only to breed. Okapis are herbivores, feeding on tree leaves and buds, grasses, ferns, fruits, and fungi. Rut in males and estrus in females does not depend on the season. In captivity, estrus cycles recur every 15 days. The gestational period is around 440 to 450 days long, following which usually a single calf is born. The juveniles are kept in hiding, and nursing takes place infrequently. Juveniles start taking solid food from three months, and weaning takes place at six months.

Okapis inhabit canopy forests at altitudes of 500–1,500 m (1,600–4,900 ft). The International Union for the Conservation of Nature and Natural Resources classifies the okapi as endangered. Major threats include habitat loss due to logging and human settlement. Illegal mining and extensive hunting for bushmeat and skin have also led to a decline in populations. The Okapi Conservation Project was established in 1987 to protect okapi populations.

Etymology and taxonomy

Strips cut from the striped part of the skin of an okapi, sent home by Sir Harry Johnston, were the first evidence of the okapi's existence to reach Europe.

Although the okapi was unknown to the Western world until the 20th century, it may have been depicted since the early fifth century BCE on the façade of the Apadana at Persepolis, a gift from the Ethiopian procession to the Achaemenid kingdom.[2][3]

For years, Europeans in Africa had heard of an animal that they came to call the African unicorn.[4][5] The animal was brought to prominent European attention by speculation on its existence found in press reports covering Henry Morton Stanley's journeys in 1887. In his travelogue of exploring the Congo, Stanley mentioned a kind of donkey that the natives called the atti, which scholars later identified as the okapi.

When the British special commissioner in Uganda, Sir Harry Johnston, discovered some Pygmy inhabitants of the Congo being abducted by a showman for exhibition, he rescued them and promised to return them to their homes. The Pygmies fed Johnston's curiosity about the animal mentioned in Stanley's book. Johnston was puzzled by the okapi tracks the natives showed him; while he had expected to be on the trail of some sort of forest-dwelling horse, the tracks were of a cloven-hoofed beast.[6]

Illustration from an original painting by Sir Harry Johnston, based on preserved skins (1901)

Though Johnston did not see an okapi himself, he did manage to obtain pieces of striped skin and eventually a skull. From this skull, the okapi was correctly classified as a relative of the giraffe; in 1901, the species was formally recognized as Okapia johnstoni.[7]

Okapia johnstoni was first described as Equus johnstoni by English zoologist Philip Lutley Sclater in 1901.[8] The generic name Okapia derives either from the Mbuba name okapi[9] or the related Lese Karo name o'api, while the specific name (johnstoni) is in recognition of Johnston, who first acquired an okapi specimen for science from the Ituri Forest.[7][10]

In 1901, Sclater presented a painting of the okapi before the Zoological Society of London that depicted its physical features with some clarity. Much confusion arose regarding the taxonomical status of this newly discovered animal. Sir Harry Johnston himself called it a Helladotherium, or a relative of other extinct giraffids.[11] Based on the description of the okapi by Pygmies, who referred to it as a "horse", Sclater named the species Equus johnstoni.[12] Subsequently, zoologist Ray Lankester declared that the okapi represented an unknown genus of the Giraffidae, which he placed in its own genus, Okapia, and assigned the name Okapia johnstoni to the species.[13]

In 1902, Swiss zoologist Charles Immanuel Forsyth Major suggested the inclusion of O. johnstoni in the extinct giraffid subfamily Palaeotraginae. However, the species was placed in its own subfamily Okapiinae, by Swedish palaeontologist Birger Bohlin in 1926,[14] mainly due to the lack of a cingulum, a major feature of the palaeotragids.[15] In 1986, Okapia was finally established as a sister genus of Giraffa on the basis of cladistic analysis. The two genera together with Palaeotragus constitute the tribe Giraffini.[16]

Evolution

Despite the vast difference in neck length, the okapi (left) and the giraffe (right) both have seven cervical vertebrae (as do all mammals except for manatees and sloths).

The earliest members of the Giraffidae first appeared in the early Miocene in Africa, having diverged from the superficially deer-like climacoceratids. Giraffids spread into Europe and Asia by the middle Miocene in a first radiation. Another radiation began in the Pliocene, but was terminated by a decline in diversity in the Pleistocene.[17] Several important primitive giraffids existed more or less contemporaneously in the Miocene (23–10 million years ago), including Canthumeryx, Giraffokeryx, Palaeotragus, and Samotherium. According to palaeontologist and author Kathleen Hunt, Samotherium split into Okapia (18 million years ago) and Giraffa (12 million years ago).[18] However, J. D. Skinner argued that Canthumeryx gave rise to the okapi and giraffe through the latter three genera and that the okapi is the extant form of Palaeotragus.[19] The okapi is sometimes referred to as a living fossil, as it has existed as a species over a long geological time period, and morphologically resembles more primitive forms (e.g. Samotherium).[13][20]

In 2016, a genetic study found that the common ancestor of giraffe and okapi lived about 11.5 million years ago.[21]

Description

Male okapi displaying his striking horizontal stripes

The okapi is a medium-sized giraffid, standing 1.5 m (4 ft 11 in) tall at the shoulder. Its average body length is about 2.5 m (8 ft 2 in) and its weight ranges from 200 to 350 kg (440 to 770 lb).[22] It has a long neck, and large and flexible ears. In sharp contrast to the white horizontal stripes on the legs and white ankles, the okapi's coat is a chocolate to reddish brown. The distinctive stripes resemble those of a zebra.[23] These features serve as an effective camouflage amidst dense vegetation. The face, throat, and chest are greyish white. Interdigital glands are present on all four feet, and are slightly larger on the front feet.[24] Male okapis have short, hair-covered horn-like structures called ossicones, less than 15 cm (5.9 in) in length, which are similar in form and function to the ossicones of a giraffe.[25] The okapi exhibits sexual dimorphism, with females 4.2 cm (1.7 in) taller on average, slightly redder, and lacking prominent ossicones, instead possessing hair whorls.[26][27]

The okapi shows several adaptations to its tropical habitat. The large number of rod cells in the retina facilitate night vision, and an efficient olfactory system is present. The large auditory bullae of the temporal bone allow a strong sense of hearing. The dental formula of the okapi is 0.0.3.33.1.3.3.[24] Teeth are low-crowned and finely cusped, and efficiently cut tender foliage. The large cecum and colon help in microbial digestion, and a quick rate of food passage allows for lower cell wall digestion than in other ruminants.[28]

Head of a male okapi with damaged ossicones

The okapi is easily distinguished from its nearest extant relative, the giraffe. It is much smaller than the giraffe and shares more external similarities with bovids and cervids. Ossicones are present only in the male okapi, while both sexes of giraffe possess this feature. The okapi has large palatine sinuses (hollow cavities in the palate), unique among the giraffids. Morphological features shared between the giraffe and the okapi include a similar gait – both use a pacing gait, stepping simultaneously with the front and the hind leg on the same side of the body, unlike other ungulates that walk by moving alternate legs on either side of the body[29] – and a long, black tongue (longer in the okapi) useful for plucking buds and leaves, as well as for grooming.[28]

Ecology and behaviour

Okapis are primarily diurnal, but may be active for a few hours in darkness.[30] They are essentially solitary, coming together only to breed. They have overlapping home ranges and typically occur at densities around 0.6 animals per square kilometre.[23] Male home ranges average 13 km2 (5.0 sq mi), while female home ranges average 3–5 km2 (1.2–1.9 sq mi). Males migrate continuously, while females are sedentary.[31] Males often mark territories and bushes with their urine, while females use common defecation sites. Grooming is a common practice, focused at the earlobes and the neck. Okapis often rub their necks against trees, leaving a brown exudate.[24]

The male is protective of his territory, but allows females to pass through the domain to forage. Males visit female home ranges at breeding time.[28] Although generally tranquil, the okapi can kick and butt with its head to show aggression. As the vocal cords are poorly developed, vocal communication is mainly restricted to three sounds — "chuff" (contact calls used by both sexes), "moan" (by females during courtship) and "bleat" (by infants under stress). Individuals may engage in Flehmen response, a visual expression in which the animal curls back its upper lips, displays the teeth, and inhales through the mouth for a few seconds. The leopard is the main natural predator of the okapi.[24]

Diet

The long tongue of the okapi

Okapis are herbivores, feeding on tree leaves and buds, grasses, ferns, fruits, and fungi. They are unique in the Ituri Forest as they are the only known mammal that feeds solely on understory vegetation, where they use their 18-inch-long (46 cm) tongues to selectively browse for suitable plants. The tongue is also used to groom their ears and eyes.[32] They prefer to feed in treefall gaps. The okapi has been known to feed on over 100 species of plants, some of which are known to be poisonous to humans and other animals. Fecal analysis shows that none of those 100 species dominates the diet of the okapi. Staple foods comprise shrubs and lianas. The main constituents of the diet are woody, dicotyledonous species; monocotyledonous plants are not eaten regularly. In the Ituri forest, the okapi feeds mainly upon the plant families Acanthaceae, Ebenaceae, Euphorbiaceae, Flacourtiaceae, Loganiaceae, Rubiaceae, and Violaceae.[24][31]

Reproduction

A female okapi with her calf at White Oak Conservation

Female okapis become sexually mature at about one-and-a-half years old, while males reach maturity after two years. Rut in males and estrous in females does not depend on the season. In captivity, estrous cycles recur every 15 days.[28][33] The male and the female begin courtship by circling, smelling, and licking each other. The male shows his interest by extending his neck, tossing his head, and protruding one leg forward. This is followed by mounting and copulation.[26]

The gestational period is around 440 to 450 days long, following which usually a single calf is born, weighing 14–30 kg (31–66 lb). The udder of the pregnant female starts swelling 2 months before parturition, and vulval discharges may occur. Parturition takes 3–4 hours, and the female stands throughout this period, though she may rest during brief intervals. The mother consumes the afterbirth and extensively grooms the infant. Her milk is very rich in proteins and low in fat.[28]

As in other ruminants, the infant can stand within 30 minutes of birth. Although generally similar to adults, newborn calves have long hairs around the eye (resembling false eyelashes), a long dorsal mane, and long white hairs in the stripes.[34] These features gradually disappear and give way to the general appearance within a year. The juveniles are kept in hiding, and nursing takes place infrequently. Calves are known not to defecate for the first month or two of life, which is hypothesized to help avoid predator detection in their most vulnerable phase of life.[35] The growth rate of calves is appreciably high in the first few months of life, after which it gradually declines. Juveniles start taking solid food from 3 months, and weaning takes place at 6 months. Ossicone development in males takes 1 year after birth. The okapi's typical lifespan is 20–30 years.[24]

Distribution and habitat

The okapi is endemic to the Democratic Republic of the Congo, where it occurs north and east of the Congo River. It ranges from the Maiko National Park northward to the Ituri rainforest, then through the river basins of the Rubi, Lake Tele, and Ebola to the west and the Ubangi River further north. Smaller populations exist west and south of the Congo River. It is also common in the Wamba and Epulu areas. It is extinct in Uganda.[1]

The okapi inhabits canopy forests at altitudes of 500–1,500 m (1,600–4,900 ft). It occasionally uses seasonally inundated areas, but does not occur in gallery forests, swamp forests, and habitats disturbed by human settlements. In the wet season, it visits rocky inselbergs that offer forage uncommon elsewhere. Results of research conducted in the late 1980s in a mixed Cynometra forest indicated that the okapi population density averaged 0.53 animals per square kilometre.[31] In 2008, it was recorded in Virunga National Park.[36] There is also evidence that okapis were also observed in the Semuliki Valley in Uganda by Europeans, but later became extinct in the late 1970s.[37] The Semuliki Valley provides a similar habitat to the Congo Basin.

Status

Threats and conservation

The IUCN classifies the okapi as endangered.[38] It is fully protected under Congolese law. The Okapi Wildlife Reserve and Maiko National Park support significant populations of the okapi, though a steady decline in numbers has occurred due to several threats. Other areas of occurrence are the Rubi Tele Hunting Reserve and the Abumombanzi Reserve. Major threats include habitat loss due to logging and human settlement. Extensive hunting for bushmeat and skin and illegal mining have also led to population declines. A threat that has emerged quite recently is the presence of illegal armed groups around protected areas, inhibiting conservation and monitoring actions. A small population occurs north of the Virunga National Park, but lacks protection due to the presence of armed groups in the vicinity.[1] In June 2012, a gang of poachers attacked the headquarters of the Okapi Wildlife Reserve, killing six guards and other staff[39] as well as all 14 okapis at their breeding center.[40]

The Okapi Conservation Project, established in 1987, works towards the conservation of the okapi, as well as the growth of the indigenous Mbuti people.[1] In November 2011, the White Oak Conservation center and Jacksonville Zoo and Gardens hosted an international meeting of the Okapi Species Survival Plan and the Okapi European Endangered Species Programme at Jacksonville, which was attended by representatives from zoos from the US, Europe, and Japan. The aim was to discuss the management of captive okapis and arrange support for okapi conservation. Many zoos in North America and Europe currently have okapis in captivity.[41]

Okapis in zoos

1960 Dutch newsreel about okapis in Diergaarde Blijdorp

Around 100 okapis are in accredited Association of Zoos and Aquariums (AZA) zoos. The okapi population is managed in America by the AZA's Species Survival Plan, a breeding program that works to ensure genetic diversity in the captive population of endangered animals, while the EEP (European studbook) and ISB (Global studbook) are managed by Antwerp Zoo in Belgium, which was the first zoo to have an Okapi on display (in 1919), as well as one of the most successful in breeding them.[42][43]

In 1937, the Bronx Zoo became the first in North America to acquire an okapi.[44] With one of the most successful breeding programs, 13 calves have been born there between 1991 and 2011.[45] The San Diego Zoo has exhibited okapis since 1956, and their first okapi calf was born in 1962.[46] Since then, there have been more than 60 okapis born at the zoo and the nearby San Diego Zoo Safari Park, the most recent being Mosi, a male calf born on 21 July 2017 at the zoo.[47] The Brookfield Zoo in Chicago has also greatly contributed to the captive population of okapis in accredited zoos. The zoo has had 28 okapi births since 1959.[48]

Other North American zoos that exhibit and breed okapis include: Denver Zoo and Cheyenne Mountain Zoo (Colorado); Houston Zoo, Dallas Zoo, and San Antonio Zoo (Texas); Disney's Animal Kingdom, White Oak Conservation, Zoo Miami, and ZooTampa at Lowry Park (Florida); Los Angeles Zoo, Sacramento Zoo, and San Diego Zoo (California); Saint Louis Zoo (Missouri); Cincinnati Zoo and Botanical Garden and Columbus Zoo and Aquarium (Ohio); Memphis Zoo and Nashville Zoo (Tennessee); The Maryland Zoo in Baltimore (Maryland); Sedgwick County Zoo and Tanganyika Wildlife Park (Kansas); Roosevelt Park Zoo[49] (North Dakota); Henry Doorly Zoo and Aquarium (Nebraska); Philadelphia Zoo (Pennsylvania); Potawatomi Zoo[50] (Indiana); Oklahoma City Zoo and Botanical Garden (Oklahoma); and Blank Park Zoo (Iowa).[51]

In Europe, zoos that exhibit and breed okapis include: Chester Zoo, London Zoo, Marwell Zoo, The Wild Place,[52] and Yorkshire Wildlife Park[53] (United Kingdom); Dublin Zoo (Ireland); Berlin Zoo, Frankfurt Zoo, Wilhelma Zoo, Wuppertal Zoo, Cologne Zoo, and Leipzig Zoo (Germany); Zoo Basel (Switzerland); Copenhagen Zoo (Denmark); Rotterdam Zoo and Safaripark Beekse Bergen (Netherlands); Dvůr Králové Zoo (Czech Republic); Wrocław Zoo (Poland); Bioparc Zoo de Doué and ZooParc de Beauval (France); and Lisbon Zoo (Portugal).[54]

In Asia, three Japanese zoos exhibit okapis: Ueno Zoo in Tokyo; Kanazawa Zoo and Zoorasia in Yokohama.[55]

See also

References

  1. ^ a b c d Mallon, D.; Kümpel, N.; Quinn, A.; Shurter, S.; Lukas, J.; Hart, J.A.; Mapilanga, J.; Beyers, R.; Maisels, F. (2015). "Okapia johnstoni". IUCN Red List of Threatened Species. 2015: e.T15188A51140517. doi:10.2305/IUCN.UK.2015-4.RLTS.T15188A51140517.en. Retrieved 19 November 2021.
  2. ^ The Oriental Institute of the University of Chicago, Photographic Archives Archived 8 July 2008 at the Wayback Machine; photo detail Archived 21 February 2014 at the Wayback Machine. The Oriental Institute identifies the subject as an Okapi with a question mark.
  3. ^ "Ethiopian Delegation, Apadana Staircase, Persepolis by Richard Stone". PBase. Retrieved 4 March 2023.
  4. ^ "First pictures of the okapi or the African 'unicorn'". ZME Science. 12 September 2008. Retrieved 20 February 2020.
  5. ^ "A New Deal for the Okapi, Africa's "Unicorn"". NRDC. Retrieved 20 February 2020.
  6. ^ "New hope for the elusive okapi, Congo's mini giraffe". Earth Touch News Network. Retrieved 9 November 2017.
  7. ^ a b Nowak, Ronald M. (1999) Walker's Mammals of the World. 6th ed. p. 1085.
  8. ^ Sclater, Philip Lutley (1901). "On an Apparently New Species of Zebra from the Semliki Forest". Proceedings of the Zoological Society of London. 1: 50–52 – via Biodiversity Heritage Library.
  9. ^ "okapi, n." Oxford English Dictionary. Retrieved 3 April 2020.
  10. ^ Lindsey, Susan Lyndaker; Green, Mary Neel; Bennett, Cynthia L. (1999), The Okapi: Mysterious Animal of Congo-Zaire, University of Texas Press, pp. 4–8, ISBN 0292747071
  11. ^ "Proceedings of the general meetings for scientific business of the Zoological Society of London". Proceedings of the Zoological Society of London. 2 (1): 1–5. 1901.(May to December)
  12. ^ Kingdon, Jonathan (1979). East African Mammals: An Atlas of Evolution in Africa, Volume 3, Part B. Chicago: University of Chicago Press. p. 339. ISBN 9780226437224.
  13. ^ a b Prothero, Donald R.; Schoch, Robert M. (2002). Horns, tusks, and flippers : the evolution of hoofed mammals. Baltimore, Md.: Johns Hopkins University Press. pp. 66–67. ISBN 9780801871351.
  14. ^ Bohlin, B. (1926). "Die Familie Giraffidae: mit besonderer Berücksichtigung der fossilen Formen aus China". Palaeontologica Sinica, Series C. 4: 1–179.
  15. ^ Colbert, E. H. (February 1938). "The relationships of the okapi". Journal of Mammalogy. 19 (1): 47–64. doi:10.2307/1374281. JSTOR 1374281.
  16. ^ Geraads, Denis (January 1986). "Remarques sur la systématique et la phylogénie des Giraffidae (Artiodactyla, Mammalia)". Geobios. 19 (4): 465–477. Bibcode:1986Geobi..19..465G. doi:10.1016/S0016-6995(86)80004-3.
  17. ^ Finlayson, Clive (2009). Neanderthals and Modern Humans : An Ecological and Evolutionary Perspective (Digitally printed ed.). Cambridge: Cambridge University Press. p. 25. ISBN 978-0521121002.
  18. ^ Hunt, Kathleen. "Transitional Vertebrate Fossils FAQ Part 2C". TalkOrigins. Retrieved 28 April 2015.
  19. ^ Mitchell, G.; Skinner, J. D. (2003). "On the origin, evolution and phylogeny of giraffes Giraffa camelopardalis". Transactions of the Royal Society of South Africa. 58 (1): 51–73. doi:10.1080/00359190309519935. S2CID 6522531.
  20. ^ "Why Is the Okapi Called a Living Fossil". The Milwaukee Journal. 24 June 1954.
  21. ^ Agaba, M.; Ishengoma, E.; Miller, W. C.; McGrath, B. C.; Hudson, C. N.; Bedoya Reina, O. C.; Ratan, A.; Burhans, R.; Chikhi, R.; Medvedev, P.; Praul, C. A.; Wu-Cavener, L.; Wood, B.; Robertson, H.; Penfold, L.; Cavener, D. R. (May 2016). "Giraffe genome sequence reveals clues to its unique morphology and physiology". Nature. 7: 11519. Bibcode:2016NatCo...711519A. doi:10.1038/ncomms11519. PMC 4873664. PMID 27187213.
  22. ^ Burnie & Don E. Wilson (2001). Animal (1st American ed.). New York: DK. ISBN 0789477645.
  23. ^ a b Palkovacs, E. "Okapi Okapia johnstoni". Animal Diversity Web. University of Michigan Museum of Zoology. Retrieved 17 April 2015.
  24. ^ a b c d e f Bodmer, R. E.; Rabb, G. B. (10 December 1992). "Okapia johnstoni" (PDF). Mammalian Species (422): 1–8. doi:10.2307/3504153. JSTOR 3504153. S2CID 253915266. Archived from the original (PDF) on 24 September 2015.
  25. ^ Nasoori, Alireza (2020). "Formation, structure, and function of extra‐skeletal bones in mammals". Biological Reviews. 95 (4): 986–1019. doi:10.1111/brv.12597. PMID 32338826. S2CID 216556342.
  26. ^ a b Grzimek, B. (1990). Grzimek's Encyclopedia of Mammals (Volume 5). New York: McGraw-Hill Publishing Company.
  27. ^ Solounias, N. (November 1988). "Prevalence of ossicones in Giraffidae (Artiodactyla, Mammalia)". Journal of Mammalogy. 69 (4): 845–8. doi:10.2307/1381645. JSTOR 1381645.
  28. ^ a b c d e Kingdon, Jonathan (2013). Mammals of Africa (1st ed.). London: A. & C. Black. pp. 95–115. ISBN 978-1-4081-2251-8.
  29. ^ Dagg, A. I. (May 1960). "Gaits of the Giraffe and Okapi". Journal of Mammalogy. 41 (2): 282. doi:10.2307/1376381. JSTOR 1376381.
  30. ^ Lusenge, T.; Nixon, S. (2008). "Conservation status of okapi in Virunga National Park". ZSL Conservation Report. Zoological Society of London.
  31. ^ a b c Hart, J. A.; Hart, T. B. (1989). "Ranging and feeding behaviour of okapi (Okapia johnstoni) in the Ituri Forest of Zaire: food limitation in a rain-forest herbivore". Symposium of the Zoological Society of London. 61: 31–50.
  32. ^ "Okapi Conservation Strategy and Status Review" (PDF). www.giraffidsg.org. 21 February 2018. Archived from the original (PDF) on 21 February 2018. Retrieved 21 February 2018.
  33. ^ Schwarzenberger, F.; Rietschel, W.; Matern, B.; Schaftenaar, W.; Bircher, P.; van Puijenbroeck, B.; Leus, K. (December 1999). "Noninvasive reproductive monitoring in the okapi (Okapia johnstoni)". Journal of Zoo and Wildlife Medicine. The American Association of Zoo Veterinarians. 30 (4): 497–503. PMID 10749434.
  34. ^ Jirik, Kate. "Okapia johnstoni Fact Sheet". ielc.libguides.com. San Diego Zoo Wildlife Alliance. Retrieved 28 August 2021.
  35. ^ "Rare okapi born in Rotterdam Zoo". Rotterdam Zoo. 2 September 2019. Retrieved 20 February 2020.
  36. ^ Nixon, S. C.; Lusenge, T. (2008). Conservation status of okapi in Virunga National Park, Democratic Republic of Congo. ZSL Conservation Report No. 9 (PDF). London: The Zoological Society of London.
  37. ^ Sever, Zvi (3 October 2020). "Searching for the okapi (Okapia johnstoni) in Semuliki National Park, Uganda". African Journal of Ecology. 59 (1): 286–292. doi:10.1111/aje.12796. S2CID 224839859. Retrieved 26 March 2021.
  38. ^ Hebert, Amanda (26 November 2013). "Okapi Added to IUCN'S Endangered Species List". Jacksonville, Florida: Okapi Conservation Project. Retrieved 3 June 2014.
  39. ^ Flocken, J. (29 June 2012). "Tragic Losses in the Heart of Darkness". HuffPost. Retrieved 18 April 2015.
  40. ^ Jones, P. (3 April 2013). "Infamous elephant poacher turns cannibal in the Congo". Mongabay. Retrieved 16 July 2017.
  41. ^ "Okapi SSP and EEP International Meeting". Okapi Conservation Project. Wildlife Conservation Global. Archived from the original on 18 April 2015. Retrieved 18 April 2015.
  42. ^ "Of okapis and men: Antwerp Zoo helps preserve endangered species". Flanders Today. 12 August 2016. Archived from the original on 14 August 2016. Retrieved 27 May 2018.
  43. ^ "Okapi's Half-Century" (PDF). Zooquaria. EAZA (85): 7. Spring 2014. Retrieved 23 February 2021.
  44. ^ "Bronx Zoo Debuts Its Baby Okapi". WCSNewsroom. 27 July 2009. Retrieved 19 October 2018.
  45. ^ "Baby Okapi Makes Public Debut At Bronx Zoo". newyork.cbslocal.com. 8 November 2011. Retrieved 19 October 2018.
  46. ^ "Animals & Plants | Okapi". animals.sandiegozoo.org. Retrieved 4 October 2017.
  47. ^ Peterson, Karla (23 August 2017). "Endangered okapi born at San Diego Zoo". The San Diego Union-Tribune. Retrieved 23 February 2021.
  48. ^ "Brookfield Zoo Celebrates Its 28th Okapi Birth Since 1959". chicago.cbslocal.com. 26 May 2017. Retrieved 4 October 2017.
  49. ^ "Okapi arrives at Roosevelt Park Zoo". Minot Daily News. 15 September 2017. Archived from the original on 6 August 2020. Retrieved 18 May 2020.
  50. ^ "Okapi".
  51. ^ "Okapi Conservation Project | The Americas". okapiconservation.org. Archived from the original on 5 February 2021. Retrieved 13 May 2019.
  52. ^ "Helping to protect endangered species around the world". Bristol Zoo. 17 May 2019. Retrieved 23 February 2021.
  53. ^ "Rare Okapi Arrive at Yorkshire Wildlife Park". Yorkshire Wildlife Park. 17 May 2018. Retrieved 23 February 2021.
  54. ^ "Okapi Conservation Project | Europe". okapiconservation.org. Archived from the original on 1 December 2017. Retrieved 25 November 2017.
  55. ^ "Okapi Conservation Project | Asia". okapiconservation.org. Archived from the original on 5 February 2021. Retrieved 13 May 2019.
license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN

Okapi: Brief Summary

provided by wikipedia EN

The okapi (/oʊˈkɑːpiː/; Okapia johnstoni), also known as the forest giraffe, Congolese giraffe and zebra giraffe, is an artiodactyl mammal that is endemic to the northeast Democratic Republic of the Congo in central Africa. It is the only species in the genus Okapia. Although the okapi has striped markings reminiscent of zebras, it is most closely related to the giraffe. The okapi and the giraffe are the only living members of the family Giraffidae.

The okapi stands about 1.5 m (4 ft 11 in) tall at the shoulder and has a typical body length around 2.5 m (8 ft 2 in). Its weight ranges from 200 to 350 kg (440 to 770 lb). It has a long neck, and large, flexible ears. Its coat is a chocolate to reddish brown, much in contrast with the white horizontal stripes and rings on the legs, and white ankles. Male okapis have short, distinct horn-like protuberances on their heads called ossicones, less than 15 cm (5.9 in) in length. Females possess hair whorls, and ossicones are absent.

Okapis are primarily diurnal, but may be active for a few hours in darkness. They are essentially solitary, coming together only to breed. Okapis are herbivores, feeding on tree leaves and buds, grasses, ferns, fruits, and fungi. Rut in males and estrus in females does not depend on the season. In captivity, estrus cycles recur every 15 days. The gestational period is around 440 to 450 days long, following which usually a single calf is born. The juveniles are kept in hiding, and nursing takes place infrequently. Juveniles start taking solid food from three months, and weaning takes place at six months.

Okapis inhabit canopy forests at altitudes of 500–1,500 m (1,600–4,900 ft). The International Union for the Conservation of Nature and Natural Resources classifies the okapi as endangered. Major threats include habitat loss due to logging and human settlement. Illegal mining and extensive hunting for bushmeat and skin have also led to a decline in populations. The Okapi Conservation Project was established in 1987 to protect okapi populations.

license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN