Bunolagus monticularis
Creators: name: Don E. Wilson
name: Thomas E. Lacher, Jr
name: Russell A. Mittermeier
Publisher: name: Lynx Edicions
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Lagomorpha
Leporidae
Bunolagus
Bunolagus monticularis

description: 7.
Riverine Rabbit
Bunolagus monticularis
French: Lapin des Bochimans / German: Buschmannhase / Spanish: Conejo de ribera
Other common names: Bushman Hare
Taxonomy. Lepus monticularis Thomas, 1903,
“Deelfontain, Cape Colony,” South Africa.
This species is monotypic.
Distribution. C Karoo region in South Africa (around Victoria West, Beaufort West, and Fraserburg, in Northern Cape and Western Cape provinces).
Descriptive notes. Head-body 340-470 mm, tail 70-108 mm, ear 110-120 mm, hindfoot 90-120 mm; weight 1.1-5 kg. The Riverine Rabbit is small and dark, with relatively long broad ears. Ear tips are rounded and bordered by short black hairs on outer surfaces. Pelage is soft and fluffy. Dorsal fur is grizzled blackish brown, and ventral pelage is white. Characteristic eye rings are pale, and thin dark stripes run along lowerjaws from near the mouth to bases of ears. Lower flanks, limbs, and nuchal patch are rufous. Soles of feet are covered with thick dense hairs. Tail is medium-sized, dark brown with long fluffy hairs.
Habitat. Thick riverine vegetation along seasonalrivers, dominated by Salsola glabrescens, Amaranthaceae (34-8%) and Lycium spp., Solanaceae (112%). Other important species in the habitat of the Riverine Rabbit include Pteronia eythrochaeta, Asteraceae (7:9%); Osteospermum spinescens, Asteraceae (5-3%); Kochia pubescens, Amaranthaceae (6:5%); and Galenia procumbens, Aizoacae (4%). Only a small part of riparian vegetation consists of grasses, and most plants are dicotyledons.
Food and Feeding. The Riverine Rabbit browses on flowers and leaves of dicotyledons, such as P. erythrochaeta, K. pubescens, S. glabrescens, Rosenia humilis, and species of Mesembryanthemaceae. Grasses are included in the diet when available during the wet season.
Breeding. Reproduction of the Riverine Rabbit takes place in August-May during the warm season. It has one litter per year, and litter size usually is one and sometimes two young. Females might have a postpartum estrus. Gestation lasts 35-36 days. Young are born in a nest made of maternal fur and grass in a burrow. Lengths of burrow are 20-30 cm, with a nest chamber (12-17 cm wide) at the end. Young weight c.40 g at birth, are blind, and lack fur. Riverine Rabbits close their burrow entrances with soil and twigs when not in use.
Activity patterns. There is no specific information available for this species, but the Riverine Rabbit is no doubt nocturnal.
Movements, Home range and Social organization. The Riverine Rabbit lives alone and has a polygamous mating system. Average home range is 20-9 ha for males and 12-9 ha for females. There is a low degree of intrasexual home range overlap.
Status and Conservation. Classified as Critically Endangered on The IUCN Red List. The Riverine Rabbit waslisted as endangered in the 1986 South African National Red Data Book. It occurs only in a small area of ¢.86 km? In historic times,its distribution included riverine vegetation in districts of Sutherland and Calvinia (c.136 km?), but extensive surveys suggest that it has disappeared from these areas. Current population is fragmented and declining and estimated at less than 250 breeding pairs. None of the ten subpopulations is estimated at more than 50 individuals. Moreover, these subpopulations seem to be isolated from each other by anthropogenic barriers, and dispersal of individuals among them is impossible. In the past 70 years, there has been a rapid decline of the population by more than 60% due to a loss of 50-60% of suitable habitat. Habitat has been lost as a result of cultivation (past) and livestock farming (ongoing). Other threats to the Riverine Rabbit include hunting for sport and by farm workers and accidental mortality in traps set for pests on farmlands. Moreover, reduction of Black-backed Jackals (Canis mesomelas) has resulted in an increase of Wildcats (Felis silvestris lybica) and Caracals (Caracal caracal)—main predators of the Riverine Rabbit. Population decline has been arrested due to a decrease in cultivation and public awareness and establishment of conservation areas. An overall population decline of 10% or more is predicted to continue through 2022. Recommendations are to conduct further research on biology and ecology of the Volcano Rabbit, establish management plans for wild populations and their habitats, study limiting factors, increase public awareness, and start a captive breeding program.
Bibliography. Duthie (1989), Duthie & Robinson (1990), Duthie et al. (1989), Happold (2013c), Robinson (1981), South African Mammal CAMP Workshop (2013).
description: Published as part of Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Leporidae, pp. 107-148 in Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona :Lynx Edicions on page 112, DOI: 10.5281/zenodo.6625539