Mountain Zebra
There are two subspecies of the Mountain Zebra. They are the Cape Mountain Zebra and the Hartmann's Mountain Zebra. The mountain zebras have a dewlap. Like all extant zebras, mountain zebras are boldly striped in black or dark brown, and no two individuals look exactly alike. The whole body is striped except for the belly. Adult mountain zebras have a head-and-body length of 2.1-2.6 m and a tail of 40-55 cm long. Wither height ranges from 1.16-1.5 m. They weigh from 204-372 kg.
Habitat
Mountain zebras are found on mountain slopes, open grasslands, woodlands, and areas with sufficient vegetation, but their preferred habitat is mountainous terrain, especially escarpment with a diversity of grass species. The picture on the right shows the range for the Cape Mountain Zebra in red and the Hartmann's Mountain Zebra in blue.
Diet
Their preferred diet is tufted grass, but in times of shortage, they browse, eating bark, twigs, leaves, buds, fruit, and roots. They drink every day. When no surface water is available due to drought, they commonly dig for groundwater in dry river beds.
Breeding
Mares give birth to one foal at a time. The foal feeds mainly on its mother's milk for about a year, after which it is weaned onto solid forage. Cape mountain zebra foals generally move away from their maternal herds sometime between the ages of 13 and 37 months. However, with Hartmann's mountain zebra, mares try to expel their foals when they are aged around 14 to 16 months. Young males may wander alone for a while before joining a bachelor group, while females are either taken into another breeding herd or are joined by a bachelor male to form a new breeding herd.
Population
According to the IUCN Red List, they are classed as Vulnerable, but their population trend is currently increasing. Based on recent survey data, the global population size of Hartmann’s Mountain Zebra is about 33,265 (191 mature individuals in Angola, 592-724 in South Africa, and 32,416 in Namibia), with at least 1,714 Cape Mountain Zebra (in South Africa), resulting in a total global population of 34,979 mature Mountain Zebra.
Threats
Hartmann’s Mountain Zebra remains at risk of catastrophic decline under future droughts, as experienced in the early 1980s. The greatest current threat to Cape Mountain Zebra is further loss of genetic diversity through inbreeding, caused by small subpopulation sizes and/or 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); the exception being De Hoop Nature Reserve, which consists of individuals from MZNP and Kammanassie Nature Reserve. Two-thirds of the entire genotype is therefore located in just two populations (Kammanassie and Gamkaberg Nature Reserve), while the remaining third comprises MZNP and reintroduced populations. Currently, the South African population of Cape Mountain Zebra is highly fragmented into a large number of small subpopulations yet little metapopulation management is practised. Founder groups are often small (50% of subpopulations have had a founder population smaller than the recommended 14 animals, and genetic exchange between subpopulations is poor (73% of privately-owned subpopulations 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 and financial resources will be utilized for successful implementation of the plan) is essential in ensuring the long-term survival of Cape Mountain Zebra.
Cape Mountain Zebra were once extensively hunted for their skins, because they competed with livestock for grazing, and allegedly because they broke fences. Today, however, the greatest threat to the Cape subspecies may stem from the risk of hybridization with Hartmann’s Mountain Zebra and Plains Zebra. Hybridisation risk also exists for Hartmann’s Mountain zebra: possible hybridisation between mountain zebra and plains zebra have been reported for some years in the Otjovasandu area of Etsoha NP where the two species overlap. A recent analysis of faecal DNA using microsatellite markers in samples of 21 of each species from Otjovasandu supports both hybridization and introgression. However, we do not know it this is part of a normal hybrid zone or if it is an artifact, perhaps caused by the boundary fence artificially keeping the two species in closer contact throughout the year than would be the case if mountain zebra were free to move westward. Hybridisation is also reported between the HMZ and donkeys in Angola.
In Namibia, there is commercial trade in Hartmann’s Mountain Zebra skins. Populations need to be carefully monitored so that harvesting does not adversely affect population viability. However, economical incentives provided through sustainable hunting also help improve prospects of coexistence with cattle farmers who occupy much of the range. Hartmann's Mountain Zebra are reportedly being harvested at a rate of about 2,000-3,000 per year, which may exceed their rate of population growth (e.g., Cape Mountain Zebra in Gamka Mountain Nature Reserve increase at about 5% per year).
A poorly understood, but emerging, threat is that of reintroduced large predators into areas containing subpopulations of Cape Mountain Zebra. This includes Lion (Addo Elephant, Mountain Zebra and Karoo national parks) and Cheetah (MZNP, some private reserves). Data indicate that Cape Mountain Zebra were preferred prey for Lion in Karoo National Park, and anecdotal evidence suggests that cheetah suppressed population growth in at least one privately-owned population. Further research is needed to assess the extent and implications of this threat.
Conservation
Formally protected areas, and areas of good habitat, are crucial for the conservation of Mountain Zebra, particularly in South Africa. Since Hartmann’s Mountain Zebra need to move flexibly over very large distances in response to spatial and temporal variation in rainfall and primary production, very large areas that are connected and support suitable habitat are needed if viable populations are to survive.
For details on specific conservation actions needed for the two subspecies see their Red List accounts. In summary, crucial actions needed for Hartmann’s Mountain Zebra include better surveys of population numbers, a regional perspective to land use planning, research on zebra ecology, hybridization and human-zebra relationships. For Cape Mountain Zebra key conservation actions are development and implementation of a metapopulation management strategy and a biodiversity management plan.