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The dibatag (''Ammodorcas clarkei''), or Clarke's gazelle, is a medium-sized slender
antelope The term antelope is used to refer to many species of even-toed ruminant that are indigenous to various regions in Africa and Eurasia. Antelope comprise a wastebasket taxon defined as any of numerous Old World grazing and browsing hoofed mammals ...
native to
Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
and
Somalia Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...
. Though not a true
gazelle A gazelle is one of many antelope species in the genus ''Gazella'' . This article also deals with the seven species included in two further genera, '' Eudorcas'' and '' Nanger'', which were formerly considered subgenera of ''Gazella''. A third ...
, it is similarly marked, with long legs and neck. It is often confused with the
gerenuk The gerenuk (; so, garanuug; ''Litocranius walleri''), also known as the giraffe gazelle, is a long-necked antelope found in parts of East Africa. The sole member of the genus ''Litocranius'', the gerenuk was first described by the naturalist ...
due to their striking resemblance. The typical head-and-body length is about . They stand up to about . Male dibatag weigh between , whereas females range from . The length of the curved
horn Horn most often refers to: *Horn (acoustic), a conical or bell shaped aperture used to guide sound ** Horn (instrument), collective name for tube-shaped wind musical instruments *Horn (anatomy), a pointed, bony projection on the head of various ...
s, present only on males, is typically between . The upper parts are gray to fawn, while the
dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...
and
lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral cons ...
areas are cinnamon to
rufous Rufous () is a color that may be described as reddish-brown or brownish-red, as of rust or oxidised iron. The first recorded use of ''rufous'' as a color name in English was in 1782. However, the color is also recorded earlier in 1527 as a dia ...
(reddish brown). The underparts, rump and the insides of the legs are all white. While markings are visible on the face, there are none on the flanks or the buttocks. Dibatag are alert and secretive, and their brown coat provides an excellent
camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the ...
, making the dibatag one of the antelopes most difficult to hunt. They are diurnal animals, and navigate in very small herds. Both sexes attain
sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definitio ...
at 12 to 18 months. The species is polygynous. After a gestational period of six to seven months, a single offspring is born. Parturition usually occurs from September to November. The lifespan typically averages 10 to 12 years. Dibatag may maintain temporary
territories A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or a ...
demarcated by preorbital gland secretions, urine or feces. Primarily browsers, the dibatag feed on foliage and young shoots and shrubs. Dibatag are well adapted to semi-arid habitats, with the capability of surviving on very little or no water. Several factors including human settlement, habitat degradation, large numbers of livestock, political unrest and armed conflicts in the areas covering its range and lack of conservation measures for two to three decades in the late 20th century have now reduced the population to only a few thousand. Significant populations still occur in southern
Ogaden Ogaden (pronounced and often spelled ''Ogadēn''; so, Ogaadeen, am, ውጋዴ/ውጋዴን) is one of the historical names given to the modern Somali Region, the territory comprising the eastern portion of Ethiopia formerly part of the Harargh ...
(Ethiopia). The dibatag is listed by the
IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
as " Vulnerable".


Taxonomy and etymology

The dibatag was first described in 1891 by British zoologist
Oldfield Thomas Michael Rogers Oldfield Thomas (21 February 1858 – 16 June 1929) was a British zoologist. Career Thomas worked at the Natural History Museum on mammals, describing about 2,000 new species and subspecies for the first time. He was appoin ...
, who gave it the
scientific name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
''Ammodorcas clarkei''. It is the sole member of the genus ''Ammodorcas'', and is placed in the family Bovidae. Some authors such as Rod East of the IUCN SSC Antelope specialist group have classified it under a separate tribe Ammodorcadini. When Thomas first studied specimens from Somalia in 1891, he observed that the animal seemed to combine the horns of a
reedbuck Reedbuck is a common name for Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it ...
with the characteristic features of a gazelle (muzzle, facial markings, and anteorbital glands). At first, he considered it to be a reedbuck, though it appeared unnatural that a reedbuck should occur in the dry sandy plateau of Somalia. Thomas originally considered it a relative of the genus '' Redunca'' due to similarities in the morphology of horns, and placed it under the genus '' Cervicapra''. However, after considering further specimens, he placed it under the separate genus ''Ammodorcas''. No subspecies have been identified. The dibatag, which holds its black tail straight up when it is fleeing, gets its common name from the Somali words for 'tail' and 'erect': ''dabu'' and ''tag''. The dibatag is also known as Clarke's gazelle, after T. W. H. Clarke, an Australian big game hunter who collected the
type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...
.


Description

The dibatag is a medium-sized
antelope The term antelope is used to refer to many species of even-toed ruminant that are indigenous to various regions in Africa and Eurasia. Antelope comprise a wastebasket taxon defined as any of numerous Old World grazing and browsing hoofed mammals ...
with a slim body and long neck and legs. The typical head-and-body length is about . It stands up to about at the shoulder. The male weighs between , whereas the female ranges from . The long dark tail ends in a rounded but indistinct tassel. The tail is nearly long. The curved
horn Horn most often refers to: *Horn (acoustic), a conical or bell shaped aperture used to guide sound ** Horn (instrument), collective name for tube-shaped wind musical instruments *Horn (anatomy), a pointed, bony projection on the head of various ...
s, resembling those of reedbuck, are present only on males, with the pointing tips facing forward. The length of horns is typically between , though
Rowland Ward James Rowland Ward (1848–1912) was a British taxidermist and founder of the firm Rowland Ward Limited of Piccadilly, London. The company specialised in and was renowned for its taxidermy work on birds and big-game trophies, but it did other t ...
recorded a length of from
Somalia Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...
. This antelope is
sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
, because females tend to be smaller than males and lack horns. The species has a small, flat, pointed, wedge-shaped head with large eyes and medium-sized ears. A similarity to the gazelles is the black, branched structure in the interior of the ears. The mouth is very small and the upper lip slightly elongated. There are strong facial markings resembling those of a gazelle. A chestnut brown streak runs from the
crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...
up to the nostrils along the nose, flanked on both sides by parallel white stripes that circle the eyes. A white spot marks the throat. The soft and smooth coat is gray to fawn in the upper parts. The ventral side, rump and the insides of the legs are completely white, and the flanks and the buttocks are unmarked. The dibatag closely resembles the
gerenuk The gerenuk (; so, garanuug; ''Litocranius walleri''), also known as the giraffe gazelle, is a long-necked antelope found in parts of East Africa. The sole member of the genus ''Litocranius'', the gerenuk was first described by the naturalist ...
, with which it is
sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...
in eastern and central Somalia and southeastern Ethiopia. Both are
brachyodont The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone to ...
s and share several facial and
cranial Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...
features, along with a two-tone coloration of the
pelage Fur is a thick growth of hair that covers the skin of mammals. It consists of a combination of oily #Guard hair, guard hair on top and thick #Down hair, underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as ...
and strong thick horns (only in males). However, there are also some features distinguishing it from the gerenuk, including major morphological differences in horns, horn cores, tail,
postorbital The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some ve ...
area and
basioccipital The basilar part of the occipital bone (also basioccipital) extends forward and upward from the foramen magnum, and presents in front an area more or less quadrilateral in outline. In the young skull this area is rough and uneven, and is joined t ...
processes. The gerenuk has a longer, heavier neck and a shorter tail. A finer point of difference is the absence of an inward-curving lobe in the lower edge of the ear (near its tip) in the gerenuk.


Ecology and behavior

Dibatag are diurnal animals (they are active in the daytime). They navigate either in solitude or in very small herds, resembling the social behavior of the gerenuk. Singles and pairs are most common, though groups of up to six individuals have been reported. Generally groups of over four individuals are rarely observed. The reaction of dibatag towards gerenuk is obscure, with there being reports of their loose associations as well as avoidance of each other. These
territorial A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or a ...
animals may maintain temporary territories demarcated by
preorbital gland The preorbital gland is a paired exocrine gland found in many species of hoofed animals, which is homologous to the lacrimal gland found in humans. These glands are trenchlike slits of dark blue to black, nearly bare skin extending from the med ...
secretions, urine or feces. They defecate at fixed points and form dung piles. Males fight one another to defend their territory. Sparring is a notable part of fighting behavior: one male pushes and shoves against the neck and horns of the opponent, trying to throw him off balance. The stance is head down with the nose tucked between the forelegs for protection. Dibatags are well adapted to semi-arid habitats, with the capability of surviving on very little or no water. They meet most water requirements only from food. Their long neck and limbs enable them to place their forelegs on branches and reach higher branches. The brown pelage helps them hide in bushes. Alert and secretive, the dibatag hides in vegetation and remains motionless while watching for possible threats. When alarmed it flees in a slow and relaxed manner with the neck upright and tail erect. The antelope may even resort to
stotting Stotting (also called pronking or pronging) is a behavior of quadrupeds, particularly gazelles, in which they spring into the air, lifting all four feet off the ground simultaneously. Usually, the legs are held in a relatively stiff position. M ...
(a behavior particular to the gazelles), a kind of leaping with all four limbs in the air, but this gait is most often used during play. It gallops only when in real danger. Predators include the
cheetah The cheetah (''Acinonyx jubatus'') is a large cat native to Africa and central Iran. It is the fastest land animal, estimated to be capable of running at with the fastest reliably recorded speeds being , and as such has evolved specialized ...
, lion, spotted hyaena, black-backed jackal,
caracal The caracal (''Caracal caracal'') () is a medium-sized wild cat native to Africa, the Middle East, Central Asia, and arid areas of Pakistan and northwestern India. It is characterised by a robust build, long legs, a short face, long tufted e ...
,
Cape hunting dog The African wild dog (''Lycaon pictus''), also called the painted dog or Cape hunting dog, is a wild canine which is a native species to sub-Saharan Africa. It is the largest wild canine in Africa, and the only extant member of the genus '' L ...
and large eagles. Eagles usually target juveniles.


Diet

The dibatag is a typical browser, whose diet consists of foliage and young shoots and shrubs. It limits itself to a small area for foraging. Dibatag have hardly been observed drinking water in the wild. The elongated upper lip assists in the ingestion of thorny vegetation, while leaves are plucked off by the front teeth and mobile lips. They prefer ''
Commiphora The genus of the myrrhs, ''Commiphora'', is the most species-rich genus of flowering plants in the frankincense and myrrh family, Burseraceae. The genus contains approximately 190 species of shrubs and trees, which are distributed throughout the ...
'', ''
Acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus na ...
'', '' Boscia'', ''
Dichrostachys ''Dichrostachys'' is an Old World genus of flowering plants in the family Fabaceae. Their ''Acacia''-like leaves are bi-pinnately compound. Unlike ''Acacia'' their thorns are hardened branchlets rather than modified stipules. They are native fro ...
'' and '' Maerua'' species. They often gather in areas with leafy ''Commiphora'' stands due to the high water content of their leaves and shoots. In the rainy season, young soft grasses are preferred, while in the dry season they feed on fry fruits, flowers, buds, shrubs, and tall herbs. They choose a wide variety of species for browsing, hence no clear diet specialization is identified.


Reproduction

Both sexes attain
sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definitio ...
at 12 to 18 months. The species is polygynous. Rutting appears to be related to the onset of the wet season in several parts of the range. Observations in the
Naples Zoo Naples (; it, Napoli ; nap, Napule ), from grc, Νεάπολις, Neápolis, lit=new city. is the regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 909,048 within the city's adminis ...
show many similarities between the courtship behavior of the dibatag and that of the gerenuk. The male dibatag pursues the female; during the march his body is upright and the nose is held high. The male uses preorbital gland secretions to mark the female on her chest and rump. Flehmen, leg-tapping, urine testing and nosing of female genitalia are notable features of the courtship. Once in close contact with the female, he slowly raises his foreleg between her hindlegs; this is followed by copulation. After a gestational period of six to seven months, a single offspring is born. Parturition usually occurs from September to November, though births have been reported even in June and July. The infant remains in hiding for one or two weeks, with its mother close by. No further information on parental care is available. The lifespan of a dibatag averages 10 to 12 years.


Habitat and distribution

Dibatag inhabit a mix of different habitat types. They may occasionally visit treelands. They are thought to be more commonly found in areas where ''Commiphora'' shrubs grow. They occur within the altitude range of . Habitat preference does not vary significantly with seasons. A study published in 1972 found a greater number of the dibatag in areas rich in red soil. The dibatag is
endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
to the evergreen bushland of the
Ogaden Ogaden (pronounced and often spelled ''Ogadēn''; so, Ogaadeen, am, ውጋዴ/ውጋዴን) is one of the historical names given to the modern Somali Region, the territory comprising the eastern portion of Ethiopia formerly part of the Harargh ...
region of southeastern
Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
and adjoining parts in northern and central
Somalia Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...
. In the past their range extended from the southern parts of northern Somalia through southeastern Ethiopia and central Somalia (between the coastline of the
Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...
and bounded by the
Fafen River Fafen River is a river of eastern Ethiopia. Rising to the east of Harar, it cuts through a series of wide, flat shelves of sedimentary rocks made of sandstone, limestone, and gypsum as it descends in a south-eastern direction towards the Shebelle Ri ...
in the west and the
Shebelle River The Shebelle River ( so, Webi Shabeelle, ar, نهر شبيلي, am, እደላ) begins in the Ethiopian Highlands, highlands of Ethiopia, and then flows southeast into Somalia towards Mogadishu. Near Mogadishu, it turns sharply southwest, where ...
in the southwest). Rock paintings of two dibatag were discovered on the west bank of the river
Nile The Nile, , Bohairic , lg, Kiira , Nobiin language, Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered ...
and north of the
Aswan Dam The Aswan Dam, or more specifically since the 1960s, the Aswan High Dam, is one of the world's largest embankment dams, which was built across the Nile in Aswan, Egypt, between 1960 and 1970. Its significance largely eclipsed the previous Aswan L ...
in
Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Mediter ...
, suggesting a southward migration of the species in the
Predynastic period Prehistoric Egypt and Predynastic Egypt span the period from the earliest human settlement to the beginning of the Early Dynastic Period around 3100 BC, starting with the first Pharaoh, Narmer for some Egyptologists, Hor-Aha for others, with ...
in Egypt. Nowadays, however, the dibatag has disappeared from the majority of its historical range. From 1985 to 2006, over two decades, the overall decline has been estimated at more than 30 percent of the original population. In the northern Ogaden, the animal has become very rare owing to a high density of human settlements and large numbers of armed
pastoralists Pastoralism is a form of animal husbandry where domesticated animals (known as "livestock") are released onto large vegetated outdoor lands (pastures) for grazing, historically by nomadic people who moved around with their herds. The animal s ...
and their livestock. However, in the southern Ogaden, it is still common due to greater wealth of natural flora and fewer human settlements.


Threats and conservation

Drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D.  Jiang, A.  Khan, W.  Pokam Mba, D.  Rosenfeld, J. Tierney, an ...
s and
habitat degradation Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
are the major threats across the range. In Somalia, conservation measures have been hindered by lack of political stability due to conflicts over two to three decades in the latter half of the 20th century. During this period its habitat was adversely affected by
over-exploitation Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term app ...
of wildlife, prevalence of weapons and
deforestation Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated d ...
. In Ethiopia hunting is the most severe threat to the dibatag; locals have claimed that dibatag meat is preferred due to its excellent taste. However its brown pelage and alertness and timidity make hunting for it in dense bushes considerably difficult compared to other antelopes. The dibatag has been identified as Vulnerable by the
International Union for Conservation of Nature and Natural Resources The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
(IUCN). It has not been listed under the Washington Convention (CITES). There are no protected areas in its range. No population estimates or surveys could be made in the three decades from the 1960s to the 1990s due to political unrest and armed conflicts in the areas covering the range. The total surviving population is not known. In 1998, Rod East gave an estimate that the populations must be in only a few thousand given a total remaining range of and a population density of 0.1 to 0.3 per square kilometer. In 2006, the population in Ogaden was estimated at 1,500. The scenario is grim in Somalia: the dibatag have been overhunted, and their habitat faces destruction due to farming practices such as livestock grazing. They are also threatened by drought. It had nearly disappeared from most of the country by the early 1980s. Though locals claimed to have seen it in the central coastal hinterland even in the late 1980s, no clear surveys have been conducted since then to support this. Captive populations are not known.


References


External links


Fact sheet


{{Taxonbar, from=Q747627 Antilopini Antelopes of Sub-Saharan Africa Mammals of Somalia Mammals of Ethiopia Fauna of the Horn of Africa Mammals described in 1891 Taxa named by Oldfield Thomas Somali Acacia-Commiphora bushlands and thickets