Population status and distribution modelling of the critically endangered riverine rabbit (Bunolagus monticularis)

Abstract

The Riverine Rabbit (Bunolagus monticularis), a habitat specialist, is one of the most endangered mammals in southern Africa due to the large-scale fragmentation of Karoo riverine vegetation in South Africa that it inhabits. B. monticularis is an important indicator of ecosystem health and an umbrella species for conservation of the unique riverine ecosystems of the Karoo and the important ecological processes they maintain. This study aimed to contribute towards our understanding of B. monticularis through an assessment of historical survey data to better understand population status and distribution. Geospatial analysis using GIS and distribution modelling was done using Maxent. Extent of occurrence for the species is 54,227 km2 and area of occupancy 2,943 km2. Population size estimates of between 157 and 207 mature individuals indicate extremely low population size for B. monticularis and along with the estimate that no subpopulation contains more than 50 mature individuals, supports the species’ continued listing as Critically Endangered under IUCN Red List criteria C2a(i). Maxent models performed well in terms of predictive ability and fit and continue to be a useful tool for assessing potential future conservation and management actions for this species.