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the web of life in southern Africa

Bunolagus monticularis (Riverine rabbit)

Deelfontein hare, river hare, bushman hare, bushman rabbit [English]; rivierkonyn, vleihaas, doekvoetjie, boshaas, pondhaas [Afrikaans]; Buschhase [German]; lièvre des buissons [French]

Life > Eukaryotes > Opisthokonta > Metazoa (animals) > Bilateria > Deuterostomia > Chordata > Craniata > Vertebrata (vertebrates)  > Gnathostomata (jawed vertebrates) > Teleostomi (teleost fish) > Osteichthyes (bony fish) > Class: Sarcopterygii (lobe-finned fish) > Stegocephalia (terrestrial vertebrates) > Reptiliomorpha > Amniota > Synapsida (mammal-like reptiles) > Therapsida > Theriodontia >  Cynodontia > Mammalia (mammals) > Placentalia (placental mammals) > Euarchontaglires > Glires > Lagomorpha (rabbits, hares and pikas) > Family: Leporidae (rabbits, hares)

Identification

The Riverine rabbit has a typical rabbit shape but the body is more elongated and the ears are longer and more hare-like. Distinguishing facial marks include a distinctive white eye ring around each eye and a black brown stripe along the sides of the lower jaw. The tail is uniformly brown and resembles a “pom-pom”. The coat colour is variable but is a reddish-brown shade grizzled with black, the underparts are a drab gray.

Size

Body length 52 cm; weight range 1.4 -1.9 kg.

Distribution and habitat

The Riverine Rabbit is endemic to the central Karoo Desert of South Africa’s Cape Province (Northern and Western Cape). Found in river catchments in the south Central Karoo between Beaufort West and Williston, and Sutherland and Victoria West. It is a habitat specialist occupying a very restricted and specialized riverine shrubland niche. The dense and diverse vegetation provides shelter from heat and predators and a balanced diet. The soft and deep silt soils are of critical importance to the species as it uses these soils for burrowing and constructing breeding dens. Its range has halved due to habitat destruction as a consequence of agricultural development.

General behaviour

Solitary and nocturnal, feeding at night and resting during the day in shallow depressions (forms) that are scraped out under Karoo shrubs.

Food

Predominantly a browser it eats the flowers and leaves of Karoo shrubs. It grazes on new grass shoots during the wet season.

Reproduction

It is the only indigenous burrowing rabbit in Africa and depends on the soft alluvial soils in the river floodplains to construct stable breeding stops (burrows). The nest is lined with grass and belly fur from the mother. When the young occupy the burrow the entrance is plugged with soil and twigs to camouflage it from predators. With the erratic rainfall regime of the Karoo the condition of vegetation is most likely to play an important role in the reproduction of the Riverine Rabbit. One or two helpless young (“kittens”) are born during August through May after a 35-36 day long gestation period. They are blind, hairless and reared in a lined burrow. Population growth is very slow as a female only produces an average of 4 young in her lifetime of two to three years.

Life span

2 – 3 years.

History

The Riverine rabbit was first discovered in 1901 by a British trooper at Deelfontein in the Karoo. Two specimen were sent to the British Museum of Natural History where Oldfield Thomas, a researcher of the museum, described them as being "of an entirely different type to anything hitherto known, either from South Africa or from elsewhere“. In 1978 during a research project by the Mammal Research Institute of the University of Pretoria on southern African hares and rabbits - further rabbits were seen near Victoria West. Genetic studies confirmed the fact that the Riverine Rabbit is a rabbit and not a hare species. They are not closely related to other Southern African hare and rabbit species. It’s closest living relatives includes the Amami Rabbit from Japan, the Hispid Hare from India and the domestic rabbit (Oryctolagus cuniculus) originally only from Europe.

Names

It is known by several common names:

  • Boshaas and vleihaas, these names arose from its occurrence in the relatively moist and dense habitat.

  • "Doekvoetjie", refers to the broad hind paws which are furred underfoot.

  • "Pondhaas", during the 1940s the curator of the Kaffrarian Museum offered a pound for each riverine rabbit brought to him.

  • Bushman Rabbit or Hare, Deelfontein Hare.

Conservation

Threats:

The riverine rabbit is one of Southern Africa’s most endangered mammals. Its ENDANGERED status was first recognised in 1981. During 2002 its conservation status upgraded to CRITICALLY ENDANGERED. With an estimated 250 or less mature individuals in the wild today (with less than 1500 in total) the species is at an extremely high risk of extinction. The following factors have contributed to population reduction.

  • The most serious threat to the survival of the riverine rabbit is the fragmentation and loss of its unique habitat type. The destruction and modification of the Karoo’s unique riverine habitats due to overgrazing and other agricultural practices has had a significant impact on the rabbit’s population over the past century. Fertile riverine soil is preferred for cultivation. Upwards of 65% of the original riparian vegetation has been lost due to cultivation.

  • Soil erosion causes more habitat loss.

  • Overgrazing damages the vegetation and leads to the loss of important food sources.

  • Wood collection and bush clearing removes plant cover exposing the rabbits to predators and heat.

  • Hunting with snares, gin traps and dogs also threatens their survival. Traditional hunting by farm labour staff is still very widely practised and rabbits and hares might still be hunted throughout the Karoo region to provide a varied menu.

  • Dams, weirs and other constructions transform the riverbanks and create barriers to natural movement, isolating populations.

Conservation strategy

The Riverine rabbit acts as an indicator species for these river zones as its extinction in many areas of its former natural distribution range indicates the degradation, fragmentation and loss of riverine vegetation. It is also a Karoo flagship species and all efforts to conserve the Riverine rabbit will be beneficial to other plants and animals in this ecoregion.

The Riverine rabbit can only be protected effectively if its distribution is accurately known. Intensive habitat evaluation and mapping exercises in the Western and Northern Cape supply necessary data to determine the current distribution area of the rabbit. Although valuable research has been carried out, still little is known about the biology and ecology of the Riverine rabbit. Therefore research on the species and its habitat is providing crucial information on which decisions will be based for the species conservation. It has also been crucial to involve local people and farmers in order to obtain all essential data, and to engage farmers and local communities in activities to preserve the species and the precious remaining habitat. Besides establishing and implementing effective environmental education and awareness programmes, efforts to protect the Riverine rabbit are based on the formation of conservancies whereby groups of private landowners along river courses agree to prescribed conservation strategies.