Bunolagus monticularisriverine rabbit

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Geographic Range

Bunolagus monticularis is endemic to South Africa. It has an extremely limited geographic range, found only in the central and southern regions of the Karoo Desert of South Africa's Cape Province (Chapman and Flux, 1990). (Chapman and Flux, 1990)

Habitat

Bungolagus monticularis lives in dense riverine scrub along the seasonal rivers in the central Karoo Desert in the Cape Province of South Africa (Mills, 1997). (Mills and Hes, 1997)

Physical Description

Bunolagus monticularis is easily identified by the black stripe running from the corner of its mouth over its cheek, a brown woolly tail, cream-colored fur on its belly and throat, and a broad, club-like hind foot. Its tail is pale brown with a tinge of black toward the tip. Its coat is soft and silky and its limbs are short and heavily furred (Nowak, 1997). Male riverine rabbits weigh approximately 1.5 kg while females weigh about 1.8 kg (Duthie, 1987). (Duthie, 1987; Nowak, 1997)

  • Sexual Dimorphism
  • female larger
  • Range mass
    1.5 to 1.8 kg
    3.30 to 3.96 lb
  • Range length
    337 to 470 mm
    13.27 to 18.50 in

Reproduction

Bunolagus monticularis is one of the rarest mammals in the world and very little is known about its reproductive behavior other than it has a polygynous mating system. Males mate with more than one female. (Avery, June 1988)

Little is known about the life cycle of Bunolagus monticularis. Females nest in subterranean chambers and produce a single offspring per year, which is an unusually low breeding rate for rabbits (Avery, 1997). Young are born helpless and blind, and they rely on their mothers for the first part of their lives. The young weigh about 40-50 grams when born (Smithers, 1986). (Avery, June 1988; Smithers, 1986)

  • Breeding season
    Breeding occurs from August through May.
  • Range number of offspring
    1 (low)
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge

The young are altricial, underdeveloped at birth, and are born blind and hairless. They spend the first part of their lives with their mothers until they are able to move independently. Bunolagus monticularis is the only African rabbit that prepares an underground shelter for its young. This nest is 10-15 cm in diameter, 25 cm long, and lined with grass and fur (Nowak, 1997). (Nowak, 1997)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Bunolagus monticularis has never been kept in captivity. There is no information on its lifespan in the wild or in captivity currently available (Chapman and Flux, 1990). (Chapman and Flux, 1990)

Behavior

Bunolagus monticularis is nocturnal, hiding from predators by day and feeding by night. (Nowak, 1997)

Home Range

Males and females each maintain home ranges which are exclusive with regard to members of their own sex, with male home ranges about 15 ha in size and overlapping female home ranges (Duthie, 1987). (Duthie, 1987)

Communication and Perception

Food Habits

Bunolagus monticularis is predominantly a browser. It eats riparian vegetation found along seasonal rivers in the Karoo Desert. This includes salt-loving plants such as Salsola and Lycium, as well as flowers and leaves from boegoe and ink bushes (Mills, 1997). Grasses are included in the diet when these are available in the wet season. Bunolagus is also known to eat its day-time droppings which are soft, taken directly from the anus, and swallowed. By doing this, it takes in vitamin B, produced by bacteria in the hind gut, and minerals such as calcium and phosphorus are recycled (Burton, 1987). (Burton and Pearson, 1987; Mills and Hes, 1997)

  • Plant Foods
  • leaves
  • wood, bark, or stems
  • flowers
  • Other Foods
  • dung

Predation

Bunolagus is capable of jumping over one meter high bushes when being pursued by a predator. To escape predatation, it remains nocturnal, spending the day resting in a form, a shallow scrape made in the soil, under a Karoo bush (Smithers, 1986). (Smithers, 1986)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Bungolagus monticularis has a limited ecosystem role. The riverine vegetation it feeds on is known to bind soil and regenerates as the rabbit feeds on it. This means that the Riverine rabbit's feeding habbits indirectly prevents the soil from being washed away in floods (Duthie, 1987). (Duthie, 1987)

Economic Importance for Humans: Positive

The riverine habitat of Bunolagus monticularis provides many benefits for farmers. The riverine vegetation that the rabbit feeds on, causing this vegetation to regenerate, binds the soil and prevents it from being washed away in floods. Also, this vegetation promotes filtration of rainwater to groundwater, which is a benefit for the farmer who uses windmills to draw up water for his livestock (Burton, 1987). Indirectly, the habitat of Bunolagus monticularis helps humans in farming and can only be sustained if this rabbit continues to feed on this vegetation.

Conservation Status

Bunolagus monticularis is an endangered species. The most devastating threat to the riverine rabbit is the loss of its habitat. This habitat is limited to the alluvial floodplains of seasonal rivers in the central Karoo. These flood plains, only 100 - 200 m wide, are formed when the rivers overflow during floods, and deposit silt on their banks(Duthie, 1987). This soil is very good for cultivation compared with other soils found in the dry Karoo. Over the past 50 years, more than two-thirds of its habitat has been ploughed over for this purpose. Other threats to its survival include overgrazing and hunting. Overgrazing of riverine habitat opens up cover that it needs for shelter and to escape predation.

The only way to secure the long term survival of Bunolagus monticularis is to protect its natural habitat. The Dept. of Environment and Cultural Affairs has started a project which encourages farmers to form conservancies for this rabbit. Some Karoo farmers have taken this step and declared their farms Natural Heritage Sites to protect the riverine habitat and rabbit (Duthie, 1987).

Contributors

Rania Awaad (author), University of Michigan-Ann Arbor, Bret Weinstein (editor), University of Michigan-Ann Arbor.

Glossary

Ethiopian

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

World Map

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

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

coprophage

an animal that mainly eats the dung of other animals

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

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.

folivore

an animal that mainly eats leaves.

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.

nocturnal

active during the night

polygynous

having more than one female as a mate at one time

riparian

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

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

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

solitary

lives alone

tactile

uses touch to communicate

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

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

viviparous

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

References

Avery, G. June 1988. Rare Rabbit. MuseNews, Volume 2 Number 6.

Burton, , Pearson. 1987. Rare Mammals of the World. Lexington, MA, USA: Stephen Greene Press.

Chapman, , Flux. 1990. Rabbits, Hares and Pikas - Status Survey and Conservation Action Plan. Gland, Switzerland: IUCN/SSC.

Duthie, A. 1987. THE ENDANGERED RIVERINE RABBIT - A RESEARCH. African Wildlife, Vol. 41, No. 4.

Macdonald, D. 1984. he Encyclopedia of Mammals. New York, NY, USA: Facts On File Publications.

Mills, G., L. Hes. 1997. The Complete Book of South African Mammals. South Africa: Struik Publishers.

Nowak, R. 1997. "Bushman Rabbit" (On-line). Accessed Nov.18, 2001 at http://www.press.jhu.edu/books/walkers_mammals_of_the_world/lagomorpha/lagomorpha.leporidae.bunolagus.html.

Smithers, R. 1986. South African red data book--terrestrial mammals. S. Afr. Natl. Sci. Programmes Rept., no. 125: 216.