A relatively small gazelle (kg), generally recognized by the warm light brown tones of their upper parts. A broad dark brown flank stripe contrasts with a pale sandy band above and pure white belly below. In bright Saharan sunlight, especially when contrasted against a backdrop of dark volcanic rocks typical of some massifs, dorcas gazelles can appear very pale, not dissimilar in overall tone to slender-horned gazelle. As in other gazelles the nearly black tail is constantly being rapidly twitched from side to side against the pure white rump. Face markings are typical of gazelles, but characteristically well defined and clean in dorcas. They often ‘pronk’ stiffly on all fours when first suspicious of a disturbance, and run fast, tail held aloft, generally with a subtly springier gait than other Saharan gazelles.Both males and females have horns which generally do not attain the length of those of adult Cuvier’s and slender-horned gazelles. Exact shape varies but male dorcas horns are usually strongly lyrate, distinguishable by more extreme backward and twisting curvatures than seen in other small Saharan gazelles. Female horns are much thinner, lighter, and less curved, though often variably hooked near the tips. In young gazelles differences in thickness, annulation and incipient curvature of horns of males and females are already apparent in close views (or in skulls in the hand) even when horns are still shorter than ear length.
Dorcas gazelles are encountered in a wide range of group sizes, partly influenced by season, habitat quality and local population density. Singletons and small groups are typical, as are herds of 20-30 in well populated areas. Bachelor groups of males do form intermittently, depending on local social conditions. In favorable pasture following localized rainfall, large numbers of dorcas may assemble in loosely scattered groups spread over a large area. Because they have such a large distribution and are found in a wide range of habitats it is probable that details of social organization will vary from place to place.
Females typically give birth to a single calf, which like other gazelles, avoids detection by hiding for the first 1-2 weeks of life, before running strongly with adults. They can survive without access to surface water, obtaining moisture through a combination of careful food plant selection, behavioral and physiological adaptations. They select nutritionally rich and/or moisture laden parts of many plant species, notably from a range of small herbs, but also browse young leaves and pods from trees such as Acacia tortilis, Maerua crassifolia and Zizyphus sp. Following rain they may turn to fresh shooting leaves of annual grasses.
Again, because of the large range and variety of habitats used by dorcas, it is likely movement patterns differ across their distribution. Detailed studies are few, but observations of e.g. coastal (Sinaï) and mountain populations (central Ahaggar) indicate relatively constant presence year round, while in more open habitats it is thought dorcas undertake local nomadic movements in response to unpredictable changes in rainfall and pasture. Local migratory movements north and south with season may occur particularly along the southern margin of their range.
The dorcas gazelle is found in a very wide range of arid habitats throughout the Sahara and bordering Sahel, though avoiding steep parts of rocky mountains. They do not appear to penetrate the treeless sand seas inhabited by slender-horned gazelles in the northern Sahara, but there are indications that in season they may travel well into better vegetated dune formations in the southern Sahara. More typically they are closely associated with areas bearing at least some scattered trees, especially Acacia spp. They are found on wadi outwash fans along the shores of the Red Sea in the east, and along some parts of the sandier Atlantic shoreline and islets in the west. They can also live in the narrow incised wadi systems between steep sided volcanic mountains, so long as there are sufficient vegetated basins, and pass nimbly over rocky mountain trails and watersheds between such sites. But the largest extant populations are associated with the extensive rolling grasslands, fixed dune systems and low hilly outcrops of the Sahel.
Until 100 years ago the dorcas gazelle was found throughout the Sahara and Sahel, from the Atlantic to the Red Sea and from the Mediterranean coast to the sahel/savanna interface of tropical Africa, with populations extending into Ethiopia, Eritrea and the Danakil depression to the south-east. There are also small populations persisting in Israel and Jordan, though the closely related dorcas representative in Saudi Arabia (Gazella saudiya) became extinct in the 1930s. On the African continent they are still found in all traditional range states except Senegal, where there is currently a re-introduction program in place. In nearly all areas dorcas populations have been substantially reduced through over-hunting and fragmented by the impact of development and agricultural expansion. Along the Mediterranean coastline human development and expansion has extinguished most of the northerly populations, with the only indigenous representatives of stocks that may have been naturally isolated to the north of the Atlas range in Morocco and Algeria, restricted to a small fenced area outside Marrakesh in Morocco.
Although long subject to traditional and more modern forms of hunting for meat and skins through most of its range, the most commonly cited primary threat to dorcas gazelles today is the advent of modern recreational hunting, which uses powerful vehicles and weaponry, to slaughter on a very large scale. This is reinforced by the ever-growing general human presence in the desert. Well and borehole development throughout the Sahel has led to massive increases in livestock and human presence, squeezing resources and space available to gazelles, while vehicle parties travel ever more widely and freely on various enterprises, legal and illegal, some shooting gazelles for food en route, others simply chasing them for thoughtless ‘fun’ or a photo. The wide distribution and flexible habitat use of this species has helped it weather these impacts better than most other large desert mammals, but the growing fragmentation of the wilderness and the unknown impacts of climate change remain long term threats.
IUCN Red List category: Vulnerable (A2cd).
This profile was kindly written by Dr. Tim Wacher of the Zoological Society of London.
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