Oribi - KwaZulu-Natal`s most threatened antelope
D T Rowe-Rowe

It is estimated that there are approximately 1500 oribi in KwaZulu- Natal, and that they occur in some 120 separate populations.The most recent figures available on the status of oribi indicated that they had become or were decreasing on more farms than on those where they were increasing. 

 
Living requirements
Before discussing the reasons for the decline, we should first consider the oribi’s habitat preferences and social organisation.
Oribi favour moist grassland on flat to gently undulating terrain, where there is both short grass and long grass during the same year.
Short grass is needed to provide easily accessible nutritious food as oribi feed very selectively on certain grasses or often only on parts of these grasses, as well as on some forbs.
Long grass is required as cover, to provide shelter from the elements and predators, as well as shelter for the young, which are left to "lie out" for the first eight to ten weeks.

It is typical that small-bodied antelopes, which feed very selectively on highly nutritious food, are widely dispersed because their chosen food items are generally not abundant. Oribi therefore, occur in pairs or small family groups. Densities range from one oribi per 30ha to one per 8 ha, depending on the quality of the habitat and how it is managed.

Reasons for decline
The oribi’s favoured habitat is unfortunately also the type of terrain best suited to agriculture or timber-growing.
In KwaZulu-Natal many areas in which oribi formerly occurred are now maize or sugar cane fields, and even greater areas have been, and are being converted to softwood and hardwood plantations.
This is not suggesting that we should discontinue producing food for the nation so that we can have more oribi, but merely pointing out some of the reasons for this antelope’s decline.

A study of the oribi’s diet revealed that at least two thirds of the food eaten consisted of grasses, which decrease if the veld is mismanaged. Veld condition, therefore, is another factor which influences oribi abundance, particularly where overgrazing has brought about detrimental changes in the species composition of the veld or where the entire farms is grazed or burnt every year.
Increase in human numbers has also led to many farms being sub divided. As properties become smaller, rural human populations increase, more dogs are kept and more fences inhibiting movement of oribi are erected. Dogs fairly easily catch oribi, and it is generally thought that poachers with dogs or uncontrolled dogs have had a serous impact on oribi numbers.

A major concern is that oribi distribution is fragmented. Some of the populations in KwaZulu-Natal are healthy, consisting of 50 to 100 animals, but there are numerous small, isolated populations, many of which are only two or three pairs. These small populations are very vulnerable to human interference or natural catastrophes; therefore they need special care.

Management
The future of the oribi depends on sufficient suitable habitat, sound veld management and protection. Game managers and farmers can contribute mainly to the last mentioned two aspects.

It is possible to provide suitable living requirements by ensuring that there is always both long grass for cover and short grass for food during the same year, and that internal fences allow oribi to move from one camp to another. Cover can be provided by having one or more "resting" camps each year, which are not grazed, burnt or mowed. The provision of short grazing can be achieved by veld burning or mowing, possibly in conjunction with rotational grazing by cattle. If wide firebreaks are burnt during early winter, this helps to provide suitable grazing until the main late winter or spring burns take place.

Highest oribi densities in KwaZulu-Natal have been recorded on properties where there is sufficient cover, wide firebreaks are burnt, flat areas are mowed at least twice during the growing season and some areas are burnt. Or, where instead of mowing, cattle are brought in to the camps to graze them whenever the grass is long enough.

Strict control on the numbers and movements of dogs should be maintained. The fewer the better. Some form of checking on the incidence of poaching needs to be practiced. In conservancy areas this is achieved by regular conservancy guard patrols, the checking of fences for snares, and the destruction of any unaccompanied dogs.

Private landowners have a very important role to play in ensuring the future of oribi; there are many more oribi on farms than in nature reserves. At present oribi are listed as "vulnerable" in the South African Red Data Book. If their numbers continue to decrease they will move into the category "Endangered", which is ominously close to extinction.

KEY POINTS
Oribi are small vulnerable animals that are sparsely distributed.
They have limited habitat tolerances favouring flat or undulating good quality grassland.They require short grass for grazing and long grass for shelter.
Both short grass and long grass must be present during the same year.
Oribi are easily killed by dogs or poachers.