Rationale
Although Nyala populations decline substantially in the past, the most recent rough abundance estimate (2013/14 counts) within South Africa is 40,398 animals, and there are estimated to be another 1,000 in Swaziland. The mature population that exists broadly within the natural range is estimated to be 16,217â22,114 animals (assuming a 55â75% mature population structure), but needs further fine-scale analysis and verification. Approximately 49% of the population occurs on private land in South Africa and their numbers are increasing due to it being a popular trophy-hunting and ecotourism species. However, many private subpopulations are intensively managed and may not be eligible for inclusion in the Red List. Including only formally protected areas within the natural distribution range yields a mature population size of 11,213â15,291 animals. There are no major threats to the species and subpopulations are considered to be stable or increasing. Provided that effective management and protection is upheld, it is likely that Nyala numbers will continue to increase on private lands. It should continue to be sustainably utilised so that private landowners are incentivised to reintroduce this species into areas of its natural range. No immediate conservation interventions are necessary but it can cause habitat degradation and lead to Bushbuck (Tragelaphus sylvaticus) declines in areas outside of its natural range, and thus regulations to prevent further introduction and naturalised subpopulations should be maintained.
Regional population effects: There is suspected to be dispersal along the northern border of South Africa between Botswana, Zimbabwe and Mozambique, through the Mapungubwe and Greater Limpopo Transfrontier areas and northeast KwaZulu-Natal. In Mozambique they are widespread south of the Zambezi with 50% in protected areas or hunting managed hunting reserves (coutadas).
Distribution
Nyala occur in subtropical/tropical areas with thickets or forests with a discontinuous natural distribution in southern Malawi (Lower Shire Valley), northern (Zambezi valley and Mana Pools National Park) and southern Zimbabwe, central and southern Mozambique, Swaziland and South Africa (including areas of the Limpopo, Mpumalanga and KwaZulu-Natal provinces). The populations in protected areas in Mozambique continue to increase, particularly in Gorongosa National Park and the Zambezi delta coutadas. Nyala from Lengwe have been used to establish a viable population on Sucoma Estate in Malawi. Although the native population of Nyala went extinct in Swaziland by the 1950s, they have been reintroduced successfully onto reserves in the middleveld and lowveld (Skinner & Chimimba 2005). They were historically thought to have occurred as far south as the Hluhluwe River (Anderson 2013) and as far west as Ellisras in Limpopo (Rautenbach 1982). There is little record of the distribution on Nyala prior to the Rinderpest epizootic in 1890s and as the Tragelaphini were particularly hard hit, it can be speculated that their natural distribution could have been wider than early records show. Nyala are impacted by cold wet conditions (Anderson 1985) and all early records of their distribution showed that they were only found in hot, low-altitude habitats below the 18° isotherm (Anderson 1976).
Since the early 1960s, animals have been translocated from game reserves in KwaZulu-Natal to other protected areas and ranches both within and significantly outside its natural range within South Africa, as well as in northern Namibia in the farming districts (Anderson 2013). Additionally, habitat change brought about by the impacts of livestock and the control of fires has favoured woody plant encroachment and the development of Nyala habitat beyond their historical range, which has allowed landowners to introduce this species. They are generally well adapted to artificial range expansion (especially if supplementary feed is provided), as long as the habitats are suitable and do not experience wet winters or extended days of frost (Anderson 2013). In the North West Province, historical accounts give the distribution as far as about Stockpoort, Limpopo River (Rautenbach 1978), which means that they conceivably could have followed the Limpopo River, and entered the North West up a fork of the Marico River, given suitable conditions, but since this evidence is lacking, they remain an extra-limital species in the province. Additionally, the species was discovered on camera traps outside of game farms in the Mositha area, which suggests that escapees have naturalised in many areas (Power 2014). This has led to animals from the North West having spread into neighbouring parts of Botswana, such as the Tuli Block (Anderson 2013).
Population trend
Trend
The global population of Nyala was estimated at over 32,000 individuals by East (1999). The current global population is estimated at c. 36,500 with population trends generally stable or increasing (IUCN SSC Antelope Specialist Group 2016). Recent rough estimates suggest that the abundance of Nyala in South Africa may be at least 30,000, with the majority (~25,000) occurring in KwaZulu-Natal (Anderson 2013). The largest subpopulations are as follows: Ndumo (4,000), Mkhuze (7,000), Hluhluwe iMfolozi (7,000) (Rowe-Rowe 1994); and greater Kruger National Park (3,000) (Anderson 2013). The Swaziland population numbers around 1,000 animals on protected areas and ranches after successful reintroduction (Monadjem 1998). Using available population estimates from both protected areas and ranchlands across the country we estimate the current (2013â2014 counts) population size to be at least 40,398 on 417 properties, which equates to 41,398 if the Swaziland population is included. Of these, formally protected areas constitute 20,683 animals on 56 reserves (of which 20,388 animals on 43 properties occur within the natural range), which means the private sector accounts for c. 49% of the total population. Most of the population exists broadly within the natural range (taken to be Limpopo, KwaZulu-Natal and Swaziland) with an estimated 29,485 animals in 122 properties. However, further scrutiny of whether such subpopulations truly occur within the natural range and whether most private subpopulations qualify as wild and free-roaming (not captive bred) is necessary for a more accurate population estimate. Using a mature population structure of 55â75%, the current mature population size within the natural range is thus estimated to be 16,217â22,114 animals. Generation length is estimated to be 5.5 years (IUCN SSC Antelope Specialist Group 2016), yielding a three generation period of c. 16 years (1999â2015). No reliable long-term subpopulation data are available to measure national population trend, but we suspect the population is stable or increasing.
In southern Africa, Zimbabwe has more than 1,000 animals (Anderson 2013), while numbers in Malawi have declined from 3,000 (East 1999) to about 1,500, most notably in the population in Lengwe National Park (which was originally created especially for this species). While still widespread in Mozambique, hunting pressure has probably reduced the population to around 3,000 (Anderson 2013). Extra-limital to the speciesâ natural range, Namibia has about 250 individuals, all on private ranches. Overall, the population is suspected to be stable or increasing within the assessment region, especially on private land.
Threats
Historically, overexploitation and diseases, such as Rinderpest, resulted in the extensive loss of Nyala throughout their native range. There also were game eradication schemes to control Nagana which would have contributed to historical Nyala declines. However, more recently, through reintroduction, introduction, and population recovery, this species is now considered stable/increasing both within and outside of its former distribution. Currently, no major threats have been identified for Nyala subpopulations. Within the assessment region, human settlement has reduced habitat availability in certain areas. However, wildlife ranching may be creating new habitat for this species. They are also subject to bushmeat poaching. For example, in Borakalalo National Park in North West (Nel 2015).
Uses and trade
Nyala are subject to hunting for meat (bushmeat) and as trophies (IUCN SSC Antelope Specialist Group 2016). It is also traded at game auctions, and has a subsistence value as meat or for recreational biltong hunters. The Nyala has major national and international value as a trophy animal and possess considerable economic value. This demand (especially for adult males by trophy hunters) has led to the artificial dispersion of Nyala from game reserves in KwaZulu-Natal to other protected areas and private ranches in areas both within and outside of their former distribution (Anderson 2013). Thus, trophy-hunting has had no negative effect on the population as its value as a trophy animal ensured an increase in numbers due to reintroductions. The rapid increase in the market price of live animals has created an incentive for landowners to manage Nyala for both live sales and the trophy hunting market. Under good conditions they breed throughout the year and in Ndumu Game Reserve, were found to have a mean calving interval of 297 days (Anderson 1984). This and the robust prices for live and trophy animals makes them a sensible option for wildlife ranches with suitable habitat and climate parameters. The current value (2014) of Nyala is R25,000 per head and record of R500,000. Additionally, there are many farmers breeding them commercially in camps, which includes selection of breeding males and other intensive management interventions.
Wildlife ranching has taken advantage of habitat changes brought about by woody plant encroachment â either as a result of overgrazing or a change in the veld burning regime. The increase in woody plants has created new habitats for Nyala and landowners have adapted to this by the introduction of Nyala outside their historic range. Nyala can be kept on very small properties as long as there is enough feed and shelter. On many farms they are freeâroaming but, especially where they are extra-limital, they are often kept in camps. The camps can be any size from ½ ha to 20 or 300 ha â depending on the vegetation type. Even if animals are bred in camps, males are often released onto bigger farms so that they can grow out and be hunted. Nyala are provided supplementary food on private properties, especially in winter â largely irrespective of whether it is their natural habitat or not.
Conservation
Although having historically disappeared from parts of their former range, they continue to survive in on well-managed protected areas in South Africa and on private land. Within the assessment region, prominent successful subpopulations of Nyala occur within Ndumo Game Reserve, Mkhuze Game Reserve, Hluhluwe-iMfolozi Game Reserve, isiMangaliso Wetland Park and Kruger National Park (East 1999; Anderson 2013). While East (1999) estimated that more than 80% of the global population occurs within protected areas, half of the population exists on private land in South Africa and will continue to increase due to commercial demand by trophy hunters (Anderson 2013). As long as effective protection and management are maintained in the key protected areas for this species and its numbers continue to increase on private land, its status is unlikely to change (IUCN SSC Antelope Specialist Group 2016).
Nyala respond well to protection, to the point where over-population can become a management problem (IUCN SSC Antelope Specialist Group 2016). This is an opportunity to integrate the sustainable use of this species into wildlife-based, rural economies.
This species causes habitat degradation and competes with Bushbuck outside of its natural range. Thus, regulation of translocation is required to prevent extra-limital movement. For example, the suitable habitat of Borakalalo Nature Reserve in the North West Province has allowed this species to flourish, and the population should be removed to prevent negative impacts on local biodiversity (Power 2014). Potentially suitable areas for reintroduction to supplement diminished relict populations include the Maputo Special Reserve and Limpopo National Park in Mozambique.
Recommendations for land managers and practitioners:
- Develop this species as a keystone within the sustainable, wildlife-based rural economy. Government must establish a programme to ensure that when viable wildlife ranches are transferred to previously disadvantaged communities they are planned and that adequate training is provided to the new owners.
- Restrict movements within South Africa to those from the South African subpopulation.
- The wildlife industry and state conservation agencies must educate general about the benefits of sustainable utilisation of wildlife in conserving the countryâs biodiversity.
Research priorities:
- Population size and trends.
- Effects of wildlife ranching on this species, and methods of creating wildlife-based economies.
- The effect of captive breeding for horn length on the overall fitness of the population. For example, it is well known in domestic animals that susceptibility to endoparasites is highly hereditary. Only selecting breeding animals for their colour, horn length and shape may reduce fitness.
Encouraged citizen actions:
- Landowners should create conservancies for this species and engage local stakeholders to create sustainable, wildlife-based rural economies.
- Report sightings on virtual museum platforms (for example, iSpot and MammalMAP), especially of free-roaming herds outside protected areas and private lands.
- Purchase and consume game meat.
