Okapia johnstoniokapi

Geographic Range

Okapis (Okapia johnstoni) are a native species found within the Ethiopian Range in sub-Saharan Africa. They are mainly limited to the central, northern, and eastern parts of the Democratic Republic of Congo. Okapis range from the Maiko Forest to the Ituri Forest. Their territory extends west into the Rubi, Tele, and Ebola river basins. There has been some evidence showing that their range has extended into western Uganda, as they are pushed towards the east by deforestation and road construction. The range of okapis is constantly decreasing as they become increasingly endangered. They are typically reclusive, so both locals and researchers are unaware of how far their range truly extends. This being said, okapis are typically found at altitudes ranging from 1,600 to 3,200 feet above sea level. (Kümpel, et al., 2015a; Mallon, et al., 2015; Toon and Stephen, 2003)

Habitat

Okapis are terrestrial animals whose territorial range can stretch anywhere from 450 to 1,500 m. They mainly reside in lush, high canopy rainforests where they eat understory foliage. The Ituri forest of Zaire, in which okapis predominantly reside, contain trees that allow little sunlight through the canopy. These patches of sunlight are suited for the foraging done by okapis. The Ituri River runs through the rainforest and is fed by over 75 inches of annual rainfall. The average temperature is 31°C, showing that okapis are able to survive in humid, wet environments. There are some swamps in the region, but okapis avoid these areas due to the wet substrate. (Bodmer and Rabb, 1992; Mallon, et al., 2015; Stanton, et al., 2014; Toon and Stephen, 2003)

  • Range elevation
    450 to 1500 m
    1476.38 to 4921.26 ft

Physical Description

Before discovering that okapis were the closest relative to giraffes (Giraffa camelopardalis), they were believed to be a part of the genus Equus due to their resemblance to horses and zebras. Their bodies are a dark reddish-brown with a velvety texture. The coats of okapis are extremely oily, which helps them wick water in their tropical rainforest environments. Their brown coats are starkly contrasted to their legs and face; their legs have white stockings with brown stripes, similar to those of a zebra. Okapis have long, black tongues, similar to giraffes. Males have short, skin-covered horns, also known as ossicones). Females lack ossicones, having hair whorls in their place. (Bodmer and Rabb, 1992; Mallon, et al., 2015; Toon and Stephen, 2003)

  • Range mass
    210 to 350 kg
    462.56 to 770.93 lb
  • Average mass
    290 kg
    638.77 lb
  • Range length
    180 to 250 cm
    70.87 to 98.43 in

Reproduction

Okapis are solitary animals, but come together to mate. Due to their elusive nature, mating rituals have only been observed in captive environments. Both males and females have their own type of marking rituals before engaging in mating. Males mark small plants with urine, while females defecate in the same places to mark their territories. Both males and females rub their necks to leave dermal exudate. For a courting pair to come in contact, females in estrus will walk for hours until they encounter a male.

Once a male and female meet, the male gets close to the female and sniffs her genital area. Courting pairs stand parallel to one another with their heads facing opposite directions to sniff and lick the genitals of their partner. Both males and females then urinate and smell the markings of their partners using flehmen. Flehmen is a method of smelling the environment using the Jacobson's organ, which is part of the olfactory system. Males then stretch their necks and kick their legs, among other body postures. If a female accepts the gestures of a male, she lowers her head and moves her tail aside. Before copulation, a mating male moves behind his mate, licks her back, and then prepares to mount her.

A non-receptive female may move forward and kick her potential mate, which results in that male striking the female with his horns. Once copulation is finished, pairs separate and females return to densely forested areas for the gestation period.

Through genetic testing, it has been determined that okapis are a polygamous and promiscuous species. This is because the majority of okapis studied in a sample area of the Okapi Faunal Reserve in the DR Congo showed high levels of genetic relations. (Bodmer and Rabb, 1992; Stanton, et al., 2015)

The reproductive cycle of okapis has only been viewed in captivity, but experts believe their behavior is similar in their natural habitat. The estrus periods of okapis are typically irregular but tend to occur every fifteen days throughout the year with an eight-day follicular phase. Once copulation has finished, the gestation period will last anywhere from 414 to 493 days, with an average of 440 days. Females exhibit swelling of their udders and vulvae about two months before birth. Females go through labor standing up, and the entire process lasts around four hours.

After birth, new mothers will ingest the placenta and groom young. Sometimes, new mothers reject their infants, striking them with their hooves and killing them. Okapis are a precocial species and are known for being "hiders". Infants will stay in a nesting area for about two months, with mothers protecting these areas with aggression. Typically, okapis reach sexual maturity around 3 years old, but there have been both younger and older cases of reproduction.

  • Breeding interval
    Okapis will breed throughout the year, with estrus occurring every 15 days.
  • Breeding season
    No particular breeding season.
  • Range number of offspring
    1 to 2
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Range gestation period
    414 to 493 days
  • Average gestation period
    440 days
  • Range weaning age
    6 to 12 months
  • Range time to independence
    9 to 12 months
  • Range age at sexual or reproductive maturity (female)
    1.7 to 3 years
  • Average age at sexual or reproductive maturity (female)
    3 years
  • Range age at sexual or reproductive maturity (male)
    2.2 to 3 years
  • Average age at sexual or reproductive maturity (male)
    3 years

Okapis rely solely on their mothers for parental investment. Beyond the act of insemination, males show no parental investment. In order to give birth, mothers retreat into densely forested areas on their own. Okapis are precocial and begin to stand 30 minutes after birth. The young will retreat to a hidden nest, where they spend most of their time. Mothers protect their young in these nests, striking aggressors that come too close. Infants are considered weaned after 6 months, but it can take up to a year. In captivity, females will suckle infants that are not their own. (Bodmer and Rabb, 1992)

  • Parental Investment
  • precocial
  • female parental care
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
  • pre-independence
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

In captivity, okapis have been known to live 15 to 30 years. However, there has not been enough data collected to understand the lifespan of okapis in the wild. In 2014, a 29-year-old okapi died, who was considered the oldest known okapi in the world. Mortality in captivity is typically caused by parasites, age, bacterial infections, fungal diseases, viral diseases, and more. Older okapis can suffer from arthritis, overgrown hooves, and worn teeth. (Bodmer and Rabb, 1992; Kümpel, et al., 2015a)

  • Range lifespan
    Status: captivity
    29 (high) years
  • Typical lifespan
    Status: captivity
    15 to 30 years

Behavior

Okapis typically live as solitary animals, but have been known to feed in small groups on certain occasions. In captivity, Okapis exhibit social grooming of necks and ear-lobes, due to the enclosed captive environment. In addition, when okapis interact in the wild, they are known to mark their territory with urine. There have been observed hierarchies, as more dominant individuals raise their heads and submissive individuals have been known to place their heads on the ground. Play behavior can include gambols and lie-and-rise play. These behaviors generally involve okapis standing up and down, wagging their tails, spinning and rolling, and more. Mock aggressive play has been seen in young males that interact. (Bodmer and Rabb, 1992)

  • Range territory size
    10.5 to 4.0 km^2

Home Range

Okapis move around their forest environments and travel many miles for food, mating, and giving birth. In the wild, okapis have home ranges that overlap with other okapis. Males can have range sizes of over 10.5 km^2 and have the ability to move 4 km every day. (Bodmer and Rabb, 1992)

Communication and Perception

Okapis are very vocal animals, mainly communicating with chuffs, moans, and bleats. Chuffs are used when two okapis meet for the first time. Bleats are typically used by young okapis to alert their mothers to show stress or alarm. Moaning is used by males to communicate to females that they are open to courtships.

Other than noise, okapis mark their territory with urine to show dominance. They will also use their movements to show dominance depending on their neck stance. If an individual has its neck raised high, that individual is showing its dominance. If its neck is on the ground, that individual is submissive. Potential mates communicate through a mixture of licking, urine marking, and neck rubbing.

Okapis are not generally aggressive animals, but will communicate through force if needed. This will include kicking and hitting the flanks of an opponent with the head or horns. (Bodmer and Rabb, 1992)

Food Habits

Okapis are ruminants that are known to browse the forest for vegetation. They have been observed eating over 100 different species of plants using their prehensile tongues, which can reach over 12 inches. Their diet is mainly focused on buds, leaves, and branches of plants, and they are known to ingest plants that are poisonous to humans. Okapis supplement their diets with sulfurous clay for minerals. Some okapis have been observed eating burnt charcoal and licking bat guano off of hollow trees. Similar to their giraffe cousins, okapis drink water with their legs splayed and knees bent. (Bodmer and Rabb, 1992; Toon and Stephen, 2003)

  • Plant Foods
  • leaves
  • roots and tubers
  • wood, bark, or stems
  • Other Foods
  • dung

Predation

Due to their natural habitat in the forests of the Democratic Republic of Congo, the primary predators of okapis are leopards (Panthera pardus). However, humans are also a main predator of okapis. Indigenous pygmies are hunter-gatherers that will set traps in the forging areas of okapis to trap them. This is not too common of an occurrence, since pygmies mostly eat smaller animals. Finally, parasites like nematodes, trematodes, and helminths are known to affect the bile ducts and livers of okapis, causing death. Okapis are not known to have special anti-predator adaptations, but they kick at predators and are generally silent unless they need to make an alarm call. (Bodmer and Rabb, 1992; Toon and Stephen, 2003)

Ecosystem Roles

Because okapis are very elusive, not much is known about their ecological roles. Most information on okapis is from observations in captive environments, where they are not constantly in contact with other species. Okapis are known to be host species for some parasites and fungi, which generally kill them. Okapis are ruminants, so they act as primary consumers and help ensure certain vegetation is not too overgrown. Okapis also provide a source of food for leopards (Panthera pardus) and indigenous pygmies (Homo sapiens) in the forest. (Bodmer and Rabb, 1992; Toon and Stephen, 2003)

Commensal/Parasitic Species
  • Monodontella giraffae

Economic Importance for Humans: Positive

Considering that okapis were only discovered in the Congo region in 1901, they have not been able to make too much of an effect on humans that are not indigenous to the Congo region. As previously mentioned, pygmies do capture and use okapis as a source of food, but that does not occur too often. Okapis tend to avoid areas of dense human populations. Due to their elusive nature and low populations, humans have started to breed more okapis in captivity to help ensure the continued survival of the species. Having okapis in areas of conservation such as the Reserve of the Okapi Conservation Project has become an area for ecotourism, where people come to see this rare species. (Bodmer and Rabb, 1992; Toon and Stephen, 2003)

Economic Importance for Humans: Negative

Okapis are not known to be harmful to humans. This generally stems from the fact that they do not naturally interact with humans. They stay far enough away from agricultural areas to not use them as food. (Bodmer and Rabb, 1992)

Conservation Status

Okapis are considered an endangered species by the IUCN Red List as of July 2015. This is generally from human-related habitat destruction. Much of their forest has been clear cut for a variety of human needs. This includes residential and commercial development, expansion of agriculture, oil drilling, logging, and military exercises. To help prevent extinction, zoos around the world have helped in breeding efforts. Under Congolese law, okapis are fully protected. They are protected in the Congo, in the RFO, and in Maiko National Park. The Okapi Conservation Project helps fight on behalf of okapis to prevent further destruction of their natural habitat while still being respectful of indigenous people. (Kümpel, et al., 2015b)

Contributors

Brooke Aguilar (author), Colorado State University, Brooke Berger (editor), Colorado State University, Galen Burrell (editor).

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

acoustic

uses sound to communicate

aposematic

having coloration that serves a protective function for the animal, usually used to refer to animals with colors that warn predators of their toxicity. For example: animals with bright red or yellow coloration are often toxic or distasteful.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nomadic

generally wanders from place to place, usually within a well-defined range.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

polygynous

having more than one female as a mate at one time

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sexual ornamentation

one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.

solitary

lives alone

tactile

uses touch to communicate

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

young precocial

young are relatively well-developed when born

References

Bodmer, R., G. Rabb. 1992. Okapia johnstoni. Mammalian Species, 422: 1-8. Accessed February 10, 2020 at https://academic-oup-com.ezproxy2.library.colostate.edu/mspecies/article/doi/10.2307/3504153/2600675?searchresult=1.

Dagg, A. 1960. Gaits of the Giraffe and Okapi. Journal of Mammalogy, 41(2): 282. Accessed February 10, 2020 at https://www-jstor-org.ezproxy2.library.colostate.edu/stable/1376381?sid=primo&origin=crossref#metadata_info_tab_contents.

Jones, C., S. Wilsher, F. Wooding, K. Benirschke, W. Allen. 2015. The binucleate cell of Okapi and Giraffe placenta shows distinctive glycosylation compared with other ruminants: A lectin histochemical study. Molecular Phylogenetics and Evolution, 83: 184-190. Accessed February 09, 2020 at https://www-sciencedirect-com.ezproxy2.library.colostate.edu/science/article/pii/S1055790314004229.

Kümpel, N., A. Quinn, E. Queslin, S. Grange, D. Mallon. 2015. Okapi (Okapia johnstoni) Conservation Strategy and Status Review. International Union for Conservation of Nature SSC Giraffe and Okapi Specialist Group. Accessed March 02, 2020 at https://www.zsl.org/sites/default/files/Okapi-conservation-strategy-2015-2025-final-EN1.pdf.

Kümpel, N., A. Quinn, S. Grange. 2015. The distribution and population status of the elusive okapi, Okapia Johnstoni. African Journal of Ecology, 53(2): 242-245. Accessed February 09, 2020 at https://onlinelibrary-wiley-com.ezproxy2.library.colostate.edu/doi/full/10.1111/aje.12221.

Lindsey, S., M. Green, C. Bennett. 1999. The Okapi: Mysterious Animal of Congo-Zaire. Austin, Texas: Austin: University of Texas Press.

Mallon, D., N. Kümpel, A. Quinn, S. Shurter, J. Lukas, J. Hart, J. Mapilanga, R. Beyers, F. Maisels. 2015. "Okapia johnstoni" (On-line). The IUCN Red List of Threatened Species. Accessed February 10, 2020 at https://www.iucnredlist.org/species/15188/51140517.

Scally, R. 2019. All About African Okapis. EZ Readers.

Stanton, D., J. Hart, N. Kümpel, A. Vosper, S. Nixon, M. Bruford, J. Ewen, J. Wang. 2015. Enhancing knowledge of an endangered and elusive species, the okapi, using non‐invasive genetic techniques. Journal of Zoology, 295: 233-242. Accessed February 10, 2020 at https://zslpublications-onlinelibrary-wiley-com.ezproxy2.library.colostate.edu/doi/full/10.1111/jzo.12205.

Stanton, D., J. Hart, P. Galbusera, P. Helsen, J. Shepard, N. Kümmel, J. Wang, J. Ewen, M. Bruford. 2014. Distinct and Diverse: Range-Wide Phylogeography Reveals Ancient Lineages and High Genetic Variation in the Endangered Okapi (Okapia johnstoni). PloS One, 9(7): 1-12. Accessed February 09, 2020 at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4090074/.

Toon, A., B. Stephen. 2003. Okapis and Giraffes (Giraffidae). Pp. 399-409 in M Hutchins, A Evan, J Jackson, D Kleiman, J Murphy, D Thoney, eds. Grzimek's Animal Life Encyclopedia, Vol. 15, 2 Edition. Gale. Accessed February 10, 2020 at https://go-gale-com.ezproxy2.library.colostate.edu/ps/retrieve.do?tabID=T003&resultListType=RESULT_LIST&searchResultsType=SingleTab&searchType=AdvancedSearchForm&currentPosition=1&docId=GALE%7CCX3406700944&docType=Article&sort=Relevance&contentSegment=&prodId=GVRL&contentSet=GALE%7CCX3406700944&searchId=R1&userGroupName=coloradosu&inPS=true.