The Riverine Rabbit inhabits dense riparian growth along the seasonal rivers in the central Karoo (Nama-Karoo shrubland). Specifically, it occurs in riverine vegetation on alluvial soils adjacent to seasonal rivers. The habitat is highly fragmented and transformed. Studies show the habitat to be 61% fragmented in certain areas (Duthie 1989). Observations from the more recently discovered southern Cape population include new records spread over thirteen sites (within three subpopulations), of which nine sites are managed as game reserves/nature reserves. The majority of Riverine Rabbit occupancy lies in the Upper Karoo Bioregion (approximately 80%), with about 12% in the Rainshadow Valley Karoo Bioregion, 4% in the Trans-Escarpment Succulent Karoo Bioregion, 3% the in Western Fynbos-Renosterveld Bioregion and 1% in the Lower Karoo Bioregion (Mucina and Rutherford 2006). For the southern population found within the Little Karoo, the presence occurs within the habitat types as described by Vlok and Schutte-Vlok (2010) including Transitional Shrublands Vegetation Type, Arid Renosterveld Habitat Type, Succulent Karoo Vegetation Type, Apronveld Habitat Type and the Randteveld Habitat Type. However, they are not restricted to the alluvial floodplains in the southern Cape (C. Bragg pers. obs. 2014) and can also occur in old lands not associated with riverine vegetation. Further habitat studies are required.

It should be noted that these are broad habitat types whereas subpopulations in the northern part of the distribution are always associated with alluvial floodplains and narrow belts of riverine vegetation adjacent to seasonal rivers on a scale that is unlikely to fit within these broader habitat types. They are thus highly reliant on the critical resource areas of Karoo riparian ecosystems. These descriptions do, however, give an indication of the general vegetation structure and composition within various parts of its range. Home range has been estimated as 12 ha (Duthie 1989). This species is elusive and nocturnal, spending daylight hours in a scrape beneath riparian vegetation. They are solitary, and will only be found in breeding pairs for short periods, or in female-juvenile pairs for rearing purposes (Duthie 1989).

This species is predominantly a browser, but is known to occasionally feed on grasses during the early wet rainy season when short, green grasses become available (Duthie 1989). When browsing, they have been found to show a particular selection for Pteronia erythrochaetha, Kochia pubescens, Salsola glabrescens and species of Aizoacae. They are unable to survive on heavily overgrazed or agriculturally transformed habitats, but have been found feeding on lucerne fields at night.

Ecosystem and cultural services: It is both a flagship species for the Karoo, as well as an indicator species of riparian habitat fringing the rivers of the Nama (Upper and Central Karoo) and the Succulent Karoo where its presence is associated with ecosystem integrity (healthy ecosystem services, such as water infiltration, vegetation cover, and soil health). Its unique habitat is of economic importance to landowners in terms of cultivation and small-stock grazing. Threats to the river ecosystems include overgrazing and anthropogenic land and river  transformation, which leads to the degradation and fragmentation of Riverine Rabbit habitat.

This species is endemic to the central Karoo region of South Africa. It is associated with the dense, discontinuous vegetation fringing the seasonal rivers. It is the only indigenous burrowing rabbit in Africa, and is dependent on soft and deep alluvial soils along the river courses for constructing stable breeding stops. Approximately 40-60% of habitat was lost or fragmented during the 1930s to 1970s due to agricultural expansion on the seasonal river flood plains across its distribution range (Robinson 1981b, Duthie et al. 1989, Duthie and Robinson 1990). Historically, this species was known to occur in five localities towards the northwestern portion of its range, along the Vis and Renoster Rivers, as well as their tributaries near Calvinia (Duthie 1989). The lack of sightings data during the last 30 years, suggests that Bunolagus monticularis is now locally extinct in these regions (Collins and Toit 2016). This is likely to be a direct consequence of the extensive agricultural expansion along riverine floodplains (Duthie et al. 1989).

A large number of surveys from 1999-2013 throughout the distribution range has improved our estimates of location and sizes of the various subpopulations, and identified a new southern population in 2004, which now consists of three known subpopulations. The southern population is distributed within three catchments: the Breede, Gouritz and Olifant River systems.

Subpopulations are defined as being made up groups of confirmed sightings along first-, second- or third-order rivers that are within a maximum of 10 km of each other. If the groups of sightings are more than 10 km from each other they are not taken as being from the same subpopulation. Due to limited information about dispersal ability of this species and the fact that known densities where home range studies were carried out showed approximately one Riverine Rabbit for every 400 m of river length, 10 km between confirmed sightings was estimated as a reasonable distance to separate subpopulations. A minimum of six sightings was taken to represent a subpopulation (potentially representing up to three breeding pairs). Where less than six sightings occurred in isolation from survey data, these were assumed to be part of the nearest subpopulation based on connectivity along the rivers.

The approximate ranges of both the northern and southern populations was calculated using Kernel Density home range estimation (buffered by 5 km) and combined to give a total extent of occurrence (EOO), estimated as 54,227 km². To calculate area of occupancy (AOO), all rivers inside the EOO were buffered by 1 km on either side. Similarly, all sightings points were buffered by a 1 km radius and were used to clip the river buffer providing a total estimate of AOO. A buffer of 1 km was chosen as most of the larger patches of riverine vegetation do not occur more than 1 km from rivers, and by buffering all rivers by 1 km, all known sightings were located within these buffered areas. AOO was thus calculated as 2,943 km². 

 This species occurs mainly outside of formally protected areas. However, it was recently discovered (2013) on the formally protected Anysberg Nature Reserve (C. Birss unpubl. data), and there is a healthy subpopulation based in the private Sanbona Wildlife Reserve (both sites in the Western Cape Province), which is in the process of achieving formal protected status through the CapeNature biodiversity stewardship programme. There is also a substantial proportion of the species’ habitat from the northern population informally protected within the Riverine Rabbit conservancies. The primary conservation interventions involve further protected area expansion, especially through stewardship programmes, and active habitat restoration.

The Drylands Conservation Programme of the Endangered Wildlife Trust (EWT-DCP) was established in August 2003 and coordinates all conservation efforts on the Riverine Rabbit and its habitat. The programme aims to conserve the biodiversity of the Karoo region, to encourage private landowners to participate in conservation stewardship and to promote integrated land management practices that can sustain the Riverine Rabbit, its habitat and many other species while providing employment for communities and facilitating ecosystem restoration on landowners’ farms. The current projects are: 

• Riparian habitat restoration: Initiated in 2007, the Riparian Habitat Rehabilitation Project develops and implements strategies to regenerate degraded riparian habitat in order to re-connect remaining riverine habitat fragments. Riparian zones perform a variety of functions including storing water, reducing floods, stabilizing river banks, improving water quality by trapping sediment and nutrients, and providing shelter and food for animals. They provide corridors for movement and migration of different species, including Riverine Rabbits, and act as a buffer between aquatic ecosystems and adjacent land uses. Additionally, maintaining the integrity of riparian areas will help mitigate the effects of climate change, which could potentially heavily impact this semi-arid region. To date, the programme has undertaken restoration interventions, including soil and water erosion control, re-vegetating, grazing reduction, and soil health technologies, of 350 ha of Bunolagus habitat, and is monitoring the recovery of the species in these areas, as well as the subsequent improvement of ecosystem services.

• Establishing alternative livelihoods: Labour for the rehabilitation project is sourced locally, thereby creating employment and developing skills in poor rural communities with few other social upliftment opportunities. Through this approach a strong component of the Riparian Habitat Rehabilitation Project lies in the conservation of water resources and regional biodiversity through community involvement. The EWT-DCP established the Indigenous Karoo Plant Nursery in Loxton (Northern Cape) to support the plant needs of the Riparian Habitat Rehabilitation Project. Community members employed by the nursery are trained to propagate indigenous plants needed for the re-vegetation of Riverine Rabbit habitat within riparian zones in the Karoo. Seed is produced on the production plot within the nursery grounds and are supplemented with seeds harvested in the veld by community members.
  

• Expanding Riverine Rabbit conservancies and stewardship: Little of the Riverine Rabbit’s remaining habitat is protected within nature reserve or national parks; the survival of the Riverine Rabbit is in the hands of private landowners, consisting mostly of farmers. Therefore the EWT‐DCP works in partnership with provincial conservation departments to involve private landowners in biodiversity conservation through the process of ‘stewardship’. Stewardship refers to the wise use, management and protection of that which has been entrusted to the landowner. Within the context of conservation, stewardship means protecting important ecosystems by effectively managing aspects such as invasive alien species, fires, and grazing and cultivation practices. The EWT-DCP works closely with the four Riverine Rabbit conservancies, encompassing an area of approximately 350,000 ha in the Northern and Western Cape provinces. The long‐term goal of the EWT‐DCP is to use these existing conservancies as a stepping stone to upgrade and declare specific and key properties as Protected Areas in terms of South Africa’s National Environmental Management: Protected Areas Act (No. 57 of 2003). A critical component of the work is to promote and encourage sustainable land-use practices amongst landowners and land managers in the Karoo through developing partnerships with the relevant stakeholders. Thus the EWT-DCP strives to mainstream sustainable land management principles into agricultural practices in the Karoo and into decisions made by policymakers.

• Environmental Education and Awareness: The EWT-DCP creates awareness about Riverine Rabbit conservation efforts with farmers, farm workers and their families, school learners, teachers, and the general public. It aims to establish custodianship by cultivating a sense of ownership for the Riverine Rabbit, its habitat and the river ecosystems of the Karoo. 

Recommendations for land managers and practitioners:

• Further surveys are needed to identify Riverine Rabbit habitat and occupancy. Hughes et al. (2008) developed a habitat model that showed potential suitable habitat east of Victoria West that might contain isolated subpopulations or offer re-introduction opportunities. The results of such surveys should feed into conservation planning. For example, the work of the Drylands Conservation Programme has succeeded in mitigating impacts of high-risk wind farms through dedicated interventions, particularly in regards to stopping development within suitable habitat. These data would also be used to develop a broad habitat map of the entire distribution range.

• Develop public recognition schemes to encourage private landowners to form conservancies and protect the Riverine Rabbit. Presence on private land should lead to the the exclusion of ranching activities in key habitat areas. This should include developing riparian grazing guidelines to inform sustainable management of riparian areas, and a user-friendly manual of cost-effective sustainable land management technologies to encourage farmers to adopt restoration and sustainable farming practices. Finally, incentives should be identified to encourage landowners to adopt such practices that benefit the species (sensu Pasquini et al. 2010).

• Develop a Riverine Rabbit monitoring tool to facilitate improved conservation outcomes, such as monitoring the impacts of conservation interventions (for example, restoration) on the density of subpopulations and prioritising resources to subpopulations that are declining.

• Development of a legal tool to address Riverine Rabbit conservation: a Biodiversity Management Plan for the species in terms of the National Environmental Management: Biodiversity Act (No. 10 of 2004). This includes investigating the genetic and ecological differences between the southern and northern populations and the development of separate conservation strategies for both.

• Although captive breeding was recommended by Collins et al. (2004), captive breeding trials in the 1990s were largely unsuccessful (Dippenaar and Ferguson 1994, Ahlmann et al. 2000). Thus, the current conservation strategy for the species does not include captive breeding as an option due to the difficulty of breeding this sensitive species in captivity and the higher chance of improving populations in the wild through concerted conservation interventions such as stewardship and habitat restoration. 

Encouraged citizen actions: 

• Landowners can create or join conservancies to protect this species and its habitat.

• Landowners can lower stocking levels to improve riparian ecosystem grazing systems; reduce the number of dogs on farms; and restore riparian habitats through Working for Water and/or the EWT-DCP.

• Landowners and the public can report sightings of individuals on virtual museum platforms (for example, iSpot and MammalMAP) or provincial conservation authorities to enhance the distribution map. For example, new sightings recorded by the public and landowners are recorded in the CapeNature database.