Mountain Zebra

Current & Historic range:  The Mountain Zebra is currently found in South Africa, Namibia, and Angola. The Cape Mountain Zebra is endemic to the Cape Floristic Region of South Africa, while Hartmann’s Mountain Zebra is found mainly in Namibia, with small populations in Angola and South Africa. It's hypothesized that in historical times the two subspecies were separated by an area devoid of mountains, the Knersvlakte. However there are no historical (pre-1920) records of Hartmann’s Mountain Zebra south of the Orange River.

Cape Mountain Zebra's historical distribution extended throughout the great escarpment range in the Cape, including the Cape Fold Belt Mountains (the southern parts of the Western Cape Province), and the southern extent of the Northern Cape province. Although once widely distributed throughout the the Cape, over-hunting and agricultural expansion reduced the population to less than 80 individuals in just five areas of the former Cape province by the 1950s. Only three remnant populations  survived: Mountain Zebra NP, Kammanassie, and Gamkaberg Nature Reserves.

The current distribution of Cape Mountain Zebra is limited to around 75 fenced subpopulations spread across their former range. Subpopulations have been reintroduced to, Karoo, Addo Elephant, Bontebok, Tankwa Karoo and Camdeboo national parks, De Hoop Nature Reserve, Commando Drift Nature Reserve, Baviaanskloof Wilderness Area and Tsolwana Nature Reserve. Two of these reserve populations (Commando Drift and Tsolwana) are possibly extralimital, as there are no historical records of the species east of the Great Fish River. The subpopulation at Gariep Dam Nature Reserve in the Free State Province is significantly extra-limital and not included in this assessment. The West Coast National Park as being within the historical range but there is some doubt about this given that it is on the coast and 70 km from the closest historically-recorded subpopulation in Picketburg. The issue of whether to include West Coast National Park to be within the subspecies’ range has not been resolved. The subpopulation at Oorlogskloof Nature Reserve in the Northern Cape lies in a historical range of Cape Mountain Zebra.

Current & Historic Populations: Mountain zebras were once widespread and numerous, but both subspecies underwent dramatic declines in the 20th centuries, and have subsequently increased. By 1950, hunting and habitat loss to agriculture reduced the Cape subspecies to 80 individuals in three relict populations in the 1950s. In 1998, the number of the Cape subspecies had increased to about 1,200 individuals, with the largest population (in the Karoo National Park), estimated to number 250. From 1985 to 1995 the annual rate of increase was reported as 8.6 %, 9.6 % between 1995 and 1998 , 8.33 % between 2002 and 2009 and 9.16% between 2009-2015. However, estimating annual growth rate trends is challenging because most subpopulations are actively managed (maintained at sustainable stocking levels) and animals are often removed or augmented, which masks true growth rate. In 2014, there was estimated to be 1,714 - 3,247 mature individuals of Cape Mountain Zebra (55%-75% of total population ).

A survey of animals on both formally protected and private properties found that the total population has grown to over 4,790 animals in 75 subpopulations. Fifty six populations (1,487 individuals) are on privately owned land and 19 are on formally protected areas (3,304 individuals). The 69% of the population remains on formally protected land and the proportion on privately-owned land (31%) has not risen since 2009, despite the increase in subpopulation number. The MZNP and Karoo NP subpopulations continue to make up a significant proportion of the population, 25% and 18%, respectively. There are therefore a total of 2,306-3,971 mature Mountain Zebra in South Africa, with an increasing population. However about 30% of Cape Mountain Zebra, and 25% of Hartmann’s Mountain Zebra are located on private land, and the Mountain Zebras on protected areas are isolated.

In 1998, the Hartmann’s Mountain Zebra population was estimated to number about 25,000, or approximately 8,300 mature individuals in Namibia. Limited data in 2008 indicated that populations were increasing on communal lands in the north-west of Namibia, where from 2000 - 2006 numbers increased from 6 to 27 individuals observed per 100 km of road surveyed. Nearly a decade of above-average rainfall likely caused this increase. The national total of Hartmann’s Mountain Zebra is currently estimated at 44,712 with an average density of 0.45 per km². This is likely an underestimate because it precludes proper estimation of animals on private farms and freehold conservancies. It should be noted that there has been a massive decline in zebras over the last 2-3 years due to the current drought. 

In Angola, a recent survey conducted by the Ministry of Environment and Tourism of Namibia in Iona National Park found an estimated subpopulation size of 263 Hartmann’s Mountain Zebra.

Threats to Species Survival: The greatest current threat to the Cape Subspecies is a loss of genetic diversity through inbreeding, caused by small subpopulation sizes and small property sizes. New subpopulations have been created through translocation of animals, with all but one of these subpopulations originating from Mountain Zebra National Park (MZNP). Two thirds of the genotype is located in just two populations (Kammanassie and Gamkaberg Nature Reserve, while the remaining third comprises of MZNP origin animals. Currently, the SA population of Cape Mountain Zebra is highly fragmented into a large number of small subpopulations yet little metapopulation management is practiced. Founder groups are often small (50% of subpopulations have had a founder populations smaller than the recommended 14 animals), and genetic exchange between subpopulations is poor (73% of private-owned herds have only ever had a single introduction event), thereby increasing the risk of inbreeding and genetic drift. Vulnerability to disease also increases due to inbreeding. The subpopulations at both Bontebok National Park and Gariep Dam Nature Reserve, which have been shown to be inbred and lack genetic diversity, have both had an outbreak of sarcoid tumours (53% and 22% of the subpopulations, respectively), indicating a general immune system breakdown. Development of a metapopulation management plan (and adoption of such plan into provincial and national conservation policy) which incorporates “resource mobilization strategies” (how human/financial resources will be used for implementation) is essential in ensuring the long-term survival of Cape Mountain Zebra.

​

Hartmann’s Mountain Zebra remains at risk of catastrophic decline under future droughts, as experienced in the early 1980s. Increasingly sophisticated farming could further disrupt movements through fencing or by preventing access to surface water. Populations need to be carefully monitored so that harvesting does not adversely affect population viability. However, economical incentives provided through sustainable hunting improve prospects of coexistence with cattle farmers who occupy much of the range. The current harvest rate of this subspecies is little understood, along with how it's effecting current populations.