The latest edition of the Red data Book of South African Mammals: A Conservation Assessment lists the Riverine Rabbit as critically endangered, elevating the species from its previous status of endangered. Surveys showed that there existed less than 250 mature individuals. The rapid population decline is due to the loss of between fifty and sixty percent of their habitat in the past 70 years. The decline may have been slowed due to a decrease in cultivation, public awareness and the establishment of conservancies. No subpopulation is estimated to contain more than 50 individuals and the subpopulations are isolated due to anthropogenic (caused directly by human interference) barriers to dispersal. The possibility of extinction is forecast to occur within the next 100 years, and the likelihood thereof is greater than 50 percent.
The major reason for the decline within the population of the Riverine Rabbit is that the habitat has become highly fragmented and transformed. Studies have shown that Riverine Rabbit habitat has been fragmented up to 67 percent in certain areas and that can be taken as representative of the entire distribution. The decrease in habitat quality and quantity is predicted to continue and is exacerbated by the isolation of subpopulations by jackal proof fencing and severe land transformation.
The size and scope of Sanbona Wildlife Reserve means the reserve is vital to the successful conservation of the Riverine Rabbit within the Little Karoo. The Wildlife Department of Sanbona has instituted a monitoring program to effectively research the population of Riverine Rabbit occurring on the reserve. The most important aspect of this program is the locating of Riverine Rabbit in the reserve through field surveys. The Rabbit locations are marked through GPS co-ordinates to give an indication of the current distribution and range of the species on the reserve. This allows the department to add to the need for scientific data on the ecology of the species in regards to dietary requirements and life history. The Riverine Rabbit has been located in the Renosterveld and Succulent Karoo vegetation types on the property..
The following data is recorded for any Riverine Rabbit sighting:
Time of Sighting, Date and Moon Phase;
Weather condition (Cloud cover, Temperature, Wind Speed and Direction);
Distance of Sighting from the Road.
Since the first Riverine Rabbit sighting in 2007, over 100 sightings have been recorded on the reserve. This shows the importance of Sanbona Wildlife Reserve in conserving habitat utilized by this Critically Endangered species.
Read more about the critically endangered Riverine Rabbit at Sanbona Wildlife Reserve in Justin Fox’s article In Search of The Impossible Five in Getaway Magazine.
Words and images by Keir Lynch
Assistant Wildlife Manager
Sanbona Wildlife Reserve