Riverine rabbit  (Bunolagus monticularis)

The riverine rabbit is classified as Critically Endangered (CR) on the IUCN Red List 2004 (1).

This elegant rabbit is one of the most endangered terrestrial mammals in Southern Africa. It has very long ears, a soft and silky coat and a uniformly brown, woolly tail. A distinctive black stripe runs from the corner of the mouth over the cheeks (2), and it has white rings around the eyes (3). The belly and throat are cream in colour and the short limbs have particularly thick fur (2).

Endemic to South Africa, the riverine rabbit is found in the semi-arid Central, Upper, Ceres, and Klein Karoo regions (2).

Inhabits areas alongside seasonal rivers with a thick cover of riverside vegetation (1).

Differing from the usual rapid breeding of most rabbit species, the riverine rabbit produces just one kitten a year. In a polygynous mating system, males make use of their large home ranges to mate with every female in their territory (2). Between August and May (3), the females will make a nest in a burrow lined with grass and fur, and blocked with soil and twigs (4). They give birth to a helpless, blind and hairless kitten 35 days after mating (5). This underdeveloped offspring will remain will its mother for some time before dispersing (2).

The riverine rabbit is nocturnal, spending the night feeding on flowers, leaves and grasses, and the day in shallow depressions under bushes, hiding from predators such as black eagles. At night the droppings are firm, but during the day they are soft and are immediately eaten after deposition. This behaviour is known as coprophagia and occurs in rabbits as their digestive system is basic, and re-ingestion allows further extraction of calcium and phosphorous, as well as the absorption of vitamin B that is produced by the bacteria of the hind gut during the initial ingestion (2).

During the last 100 years, over two thirds of the riverine rabbit’s habitat has been lost, and today, only 250 mature riverine rabbits are estimated to exist in the wild. The majority of the land in the Karoo Desert is very unfertile, but the riverine rabbit occupies the flood plains of the seasonal Karoo rivers and its tributaries, which are fertile and have therefore been ploughed extensively in some areas. Removal of the natural vegetation along the rivers and streams prevents the rabbit from constructing stable breeding burrows, due to the loss of the soft alluvial top soils, and from feeding and escaping predation (1). Overgrazing by domestic herbivores also poses a threat to the rabbits’ habitat and results in habitat degradation and fragmentation (2). As rabbits and hares are adding to the menu of farm workers, they are shot or trapped with gin traps (1).

The Endangered Wildlife Trust’s Riverine Rabbit Working Group (EWT-RRWG) was established in August 2003, with the aim of establishing and conserving an ecosystem and socioeconomic conditions in the Karoo that can support a stable population of riverine rabbits. The EWT-RRWG achieves this through surveys, research and monitoring, environmental education and awareness, habitat management and rehabilitation, and conservation stewardship programmes. At present, none of the riverine rabbit habitat is protected, and the species only occurs on private Karoo farmland. Therefore, the establishment of Riverine Rabbit Conservancies is an important aim for the EWT-RRWG. Conservancies are areas established by a voluntary agreement with private landowners who have riverine rabbits and potentially suitable habitat on their properties. So far, three have been established in the Karoo. The conservation and management of riverine rabbit populations and their habitat is outlined in the conservancy constitution, and landowners strictly control or prohibit any hunting with dogs, and the use of gin traps (7). With the EWT-RRWG raising awareness of the riverine rabbit’s threatened status, and coordinating conservation efforts, it is hoped that the risk of extinction to this rare species can be reduced.

View information on this species at the UNEP World Conservation Monitoring Centre.

For further information on this species, see:

• Riverine Rabbit Conservation Project:
  http://www.riverinerabbit.co.za
• EDGE of Existence:
  http://www.edgeofexistence.org/mammals/species_info.php?id=3