Dibatag

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The Dibatag, or Clark's gazelle, Ammodorcas clarkei, is an antelope found in sandy grasslands of Ethiopia and Somalia. Not a true gazelle, it is similarly marked with a long, furry black tail which is raised in flight. This gives rise to its name, which means "erect tail" in Somali.

The Dibatag is listed by the IUCN as "vulnerable" to extinction due to hunting and human disturbance (including war).

The Dibatag (Ammodorcas clarkei) is nearly extinct in its habitat country of origin, Somalia. Last records discovered less than 500 individuals in Somalia.

Since the species is unique and the only representative of the Ammodorcas family in the world, there is no question about its importance. The Taxon is in danger of extinction and its survival is unlikely if the causal factors continue operating. Its numbers have been reduced to such a critical level that genetic damage can not be excluded, and the habitat is so drastically influenced by war and starving men that the species is deemed to be in immediate danger of extinction in Somalia.

Taxonomy

Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Antilopinae
Tribe: Ammodorcadini
Genus: Ammodorcas
Species: Ammodorcas clarkei
Subspecies: no subspecies

Common names:
Intern.: Dibatag
Somali: Dibatag [Somali: Daba = tail; Tag = up =»= Dabatag = "Tail-Up" / Clarke actually misunderstood the first "a" - sometimes pronounces by Somalis as an "e" - as an "i"]
Swahili: Swara Dibatag
English: Dibatag, Clarke's Gazelle
German: Dibatag, Lamagazelle, Stelzengazelle
French: Le Dibatag, Gazelle de Clarke
Italian: Gazella Dibatag

Identification

caption Dibatag (Ammodorcas clarkei). (Credit: J. Bauer)

Measurements

Length of body: 152 - 168 centimeters (cm)
Tail length: 30 - 36 cm
Shoulder height: 80 - 88 cm
Horn length: 25 - 33 cm
General weight: 29 - 32 kilogram (kg)
Male weight: 28 - 35 kg
Female weight: 22 - 29 kg
Maximum age: about 10 - 12 years

Gender Differences

In general, the habitus of both sexes is quite the same. The average body weight of the male is normally higher than the female ones. While the latter is hornless, the male has horns which show 6-10 rings in the lower half. Immature animals are almost like the adults.

Shape

Size: medium-sized, gazelle-like
Lips: very mobile, front slit in upper lips
Muzzle: only a narrow naked strip between nostrils
Eyes: large brown iris
Ears: long, broadly lancet-shaped
Horns: brownish-black, only in male, reedbuck-like, curved forward at top, tips only slightly diverging from each other, round in section at base, lower half with 6-10 well developed rings, upper half smooth and pointed, evenly divergent,"sickle-like" curved up and backwards and then forwards. Females carry only a patch of dark hair at the crown.
Neck: long and slender, but not as long as in the Gerenuk and not hold so straight upright. In flight thrown forward.
Shoulders: well angled and relatively strong
Limbs: long
Hoof: hard and in proportion to lower limbs. Inner hoofs narrow and pointed - lateral hoofs very small
Tail: very long, thin, rounded, reaches hocks, well haired and with distinct tassel. Held upright or thrown up and forward in flight.
Teats: four Glands, preorbital and carpal glands present. Carpal glands with hair tufts (knee brushes)
Pedal, interdigital and inguinal glands absent.
Coat: in general short and smooth hair. Longer only on female crown, both sexes have carpal glands
Colorations: general color appears uniform dark purplish grey tinged with refocus; no lateral band.
Upper side: Crown, neck, shoulders, back, flanks, thighs, outside of legs and lower inside is cinnamon brown.
Underside: chin, throat, breast, belly, upper inside of legs and back of thighs and buttocks is white.
Voice: Nasal alarm call (briefly before fleeing) and grunting snore.
Senses: Hearing and olfactoric senses are very well developed and very good, sight is less keen

Enemies

For Adults: Cheetah (Acinonyx jubatus), Leopard (Panthera pardus), Lion (Panthera leo), Serval (Felis serval), Caracal (Felis caracal), Striped Hyaena (Hyaena hyaena), Spotted Hyaena (Crocuta crocuta), Wild Dog (Lycaon pictus)

For Fawns: Ratel (Mellivora capensis), large birds of prey

Herd structure

In groups of four to five, in maximum and very seldom of up to eight animals. Usually one adult male with up to five females, which can be accompanied by the young ones. Occurs sometimes also solitary.

Little is known about the interspecies relationship of the Dibatag, though loose associations with Gerenuk (Litocranius walleri), Soemmering's Gazelle (Gazella soemmeringi) or Swaynes Hartebeest (Alcelaphus buselaphus swaynei, which propably is already extinct in Somalia) has been described. Especially since Soemmering's Gazelle occupy a different ecological niche, but because the niches of the Dibatag and the Soemmering's Gazelle often are adjacent to each other, in the overlapping areas both species were seen in the same geographical area.

Population

The population size in Somalia was estimated to be 1,500 animals at the beginning of any serious census activities in 1967. In 1987 the max. population within the boundaries of the Somali Republic was estimated to be below 500 animals. However, continued monitoring revealed that the size of the total population might have increased again.

Distribution

Geographical distribution

Historical times

Horn of Africa, from Somalia to Ogaden (Ethiopia). From western River Djerrer, easterly and in part to coast. North up to south of the Gulis Range (locally also east of these mountains up to the North coast). In Somalia south to near Equator.

Present distribution

The Dibatag is now extinct in most areas of today's Ethiopia. Very scattered populations of this species are living in only a few remaining areas of central Somalia. While Trense (1989) mentions three isolated distributions which are east of the river Shebele in Somalia and west of the river Djerrer (Ethiopia, Ogaden), it must be stated today that hardly any Dibatag are left in the Ogaden.

Reason for decline

Already in former times locally exterminated by poaching and habitat destruction due to overgrazing by domestic livestock, which seems to put a specific pressure on one of the main feeding plants (Commiphora) of Dibatag. Especially the domestic goats are a major threat to the survival of the Dibatag, due to food-competition and distress caused by invading goat herders.

Today the ongoing war with its total oblivion of law and order as well as the serious famine will certainly extinguish the species in its last wild population within the next few years, if no action is taken.

Local distribution

Data omitted for reasons of species security. Interested scientists could write to Prof. J. Bauer, who can be contacted through the Ministry of Wildlife & Tourism, Somali Government or ECOTERRA Intl.

Habitat

The Dibatag lives mainly in sandy and grassy areas, loosely bushy plains with isolated trees and thickly or widely scattered thickets, interspersed bare patches of ground, at times with high grass. Only in or after the rainy season grass plains with small trees and low thickets are used.

Within its population area, the Dibatag can only be found within some few and specific ecological "islands". Coneo reported that the animals in Somaliland were only seen at places where "very red earth" (presumed. ferrosol, laterit), which was supposed to contain aluminium too, occurred. This observation was confirmed for Central Somalia.

Territory

Territoriality and home range are part of an ongoing study. However, it already can be stated that despite a clearly defined larger range, smaller daily or weekly territories for herded groups of females are marked out by dominant males and seasonal changes were observed following the establishment of seasonal territories in Central Somalia.

Nutrition

Food species: Leaves of trees (mainly Commiphora and Acacia ssp.), small bushes, berries (Solanum spp.), var. shrubs and grasses (when green) are taken. (a complete study is in preparation)

Feeding behavior: Like the wider spread Gerenuk (Litocranius walleri) the Dibatag's anatomy enables the animals to reach young shoots, leaves, and branch twigs from bushes and trees by standing erected on their hind legs. Often the balance is kept by leaning one of the front legs against a bigger branch or trunk. Even eating small branches and bark is reported from animals held in captivity.

The Dibatag doesn't need to drink water. Even in captivity, the water offered was not taken.

Ethology

Locomotory pattern: While walking often pacing is observed in Dibatag, though cross gait is in Dibatag the most common movement, even in flight. Only in very rare occasions, the Dibatag turns into gallop. Even when running away from enemies, gait is common. During this, the neck and head as well as the tail are hold in an upright position while passing open area. The neck is stretched forward in a flight through dense bush-land, while the tail is still up.

Defecation: Specific behavior during defecation was observed by Walther (1968) in two Dibatag, which were kept in captivity. Male and female dropped the faces on specific spots which were controlled by the male several times a day. Always the male dropped urine and faces on exactly the same spot, after having scraped it. Where faces was dropped by the female, the male smelled at it, and eventually the female faces were scraped and the male sprayed own urine and dropped faces over it. This behavior could be seen as a further indication of small territories, which need to be controlled and renewed often and are marked by the dominant males. Sometimes the long tails were wetted during urination. Walther (1968) observed in two Dibatag of different sex, how they let urine pass over their muzzles while the other animal was urinating. Flameing was observed in both animals after that process.

Comfort behavior: Walther (1960) noted a special kind of comfort behavior. the captured animals that were studied scratched themselves by using the incisors without showing any chewing.

Daily rhythm: The main feeding times are in the early morning and late afternoon. During the heat around noon the animals stand still in the shade.

Display: Stretching the neck high and the nose more vertically, the male comes close to the female from behind and caresses her hind leg from the in- or outside with his stretched front leg, which is held in an angle up to 90 degree (termed "Laufeinschlag" by Walther). As in Gerenuk, the female Dibatag is marked by the antorbital organ of the male.

Sexual behavior: Only little is known about the sexual behavior of Dibatag, but pushing the front legs and copulation jumps during running have been observed. Commonly males prove the sexual readiness of their females by letting the female’s urine passing over the muzzle.

Observations on Dibatag kept in captivity: While kept in captivity the directly orientated marking of the female by the male using the antorbital organ was observed. The same author describes a very light aggressive behavior, of the female Dibatag, which seems to be linked to situations where impressing or sexual behavior is involved. The muzzle is hereby moved powerfully towards the other animal without really touching it. In case of a great hierarchic difference between the involved animals, the suppressed individual may direct the symbolic muzzle push, "symbolischer Schnauzenstoss" as it is named by Walther (1968), not towards the dominant animal, but into the empty space. This symbolic, intraspecific and intra- and intersexual behavior could be stated in female Gerenuk, Dibatag and Kudu as well as Bushbuck, which all are hornless animals.

Dibatag resting were sometimes sitting close together but never seen more than three meters away from each other. When disturbed, a "star formation" was occupied, that means the axis of the bodies of the two animals observed form an angle between 45 and 90 degree, allowing the observation of 360 degrees of the surrounding area. This formation could be seen standing and resting. This 360 degree ("radar") standing formation was observed especially, when over-flying military aircraft created noise, whose source and direction could not be easily determined by the group of Dibatag.

Reproduction

The main breeding period in Somalia is from March to May ("Gu" season = rainy season), but in general it seems not to be restricted seasonally. The period of gestation is about 6 - 7 months, but since exact data is not available, two births a year might be possible. The details of birth, rearing and growing up are not known either, but nursing females are reported to stay close to their fawn while dependent (during first one to two weeks of life).

Trade Data

National Utilization

Dibatag is legally protected in the Democratic Republic of Somalia since 1969. All our surveys and former field reports note, however, that the legal protection does not mean actual protection. Due to lack of funds, the Somali Wildlife Department up to now could not establish a system of actual protection to the Dibatag range, specific habitats or populations. Poaching and shooting for meat was and is observed in Somalia rarely.

Legal International Trade

Only a few legal exports are recorded:

  1. 1960: to the zoo of Napoli
  2. 1980: to the zoo of Dubai

Illegal Trade

Most about the illegal trade is not known. There has been, however, a certain demand for animals of this species from the Somali Peninsula. Several illegal shipments of usually 1-2 animals.

Potential Trade Threats

Live specimen

There has been a certain market for live specimen in recent years. Offers to purchase came from both institutions and private collectors. Also some offers were reported from parties, which are said to have scrupulous records in animal care and conservation.

Some parties were willing to pay extraordinary high prices for these animals, particularly breeding pairs, if they would arrive healthy and safe at their destination. The delicacy of the species usually stopped any such trial, but a lot of animals were lost in these illegal attempts.

Parts and derivatives

There is only a minor potential market for hides. A market for curio sake (horns) did exist in Mogadishu. Several entries in trophy books actually derive from animals, who were not killed by the named trophy hunter, but whose horns were traded. (addendum: When the war started in 1991 the National Museum in Mogadishu was looted and also all Dibatag trophies were stolen).

Protection Status

Domestic Protection

Dibatag (Ammodorcas clarkei) is legally protected by the Somali Law No. 15 (1969) and its amendments of the Somali Democratic Republic. There the species is listed as prohibited game, which may not be hunted throughout the country, promising extended punishment for illegal killing or possession of derivatives.

International Protection

Ammodorcas clarkei is protected under Class B of the African Convention on the Conservation of Nature & Natural Resources (1968) and under section II of the Bonn Convention (Convention on the Conservation of migrating Species of wild animals - CMS). It is also classified as "endangered" by the U.S. Endangered Species Act and as vulnerable by the IUCN Red Data Book. It must be stated, that Convention on International Trade of Endangered Species (CITES) earlier simply forgot to list the species, though Somalia has ratified the CITES in October 1982. The African Union is urged to list the species under Class A.

Additional Protection Needs

The IUCN Red Data Book urges the establishment of adequately protected reserves and the restriction of human access and stock grazing in habitat areas. The Somali Government has taken first steps.

Information on Similar Species

There is no similar species!

Somalia and the world are now faced with the situation of genocide of a wildlife species and its total extinction, if the last individuals can not be saved. In general it can be stated, that though not enough scientific knowledge exists about the species, further action must be taken immediately and the ongoing protection activities supported.

Notes

Adapted from 100 Years from Discovery to Extinction? - Abstract from the habil. thesis: DIBATAG, Bauer, J., 1987 - JAMHUURIYADDA DIMOQRAADIGA SOOMAALIYA Somali National University, Faculty of Agriculture, Department of Botany and Range, Ecology Unit, Mogadishu, 1987 compiled for the Encyclopedia of Earth and annotated by the author: Prof. Julian BAUER P.O.BOX 3487 MOGADISHU / SOMALIA TEL.: MOG.: 21108

N.B.: Since 2005, the Ministry of Wildlife & Tourism of the newly created and internationally recognized Transitional Government of the Federal Republic of Somalia (TFG) is engaged together with Prof. Bauer to improve the present protection mechanisms and systems as well as in the establishment of another protected area for in situ conservation of the Dibatag. Islamic courts are likewise helpful - and in some cases even more effective - to protect the natural heritage.

References

  • Dibatag Census, 1987, Department of Wildlife, National Range Agency, Mogadishu.
  • Bauer, J.,1986, 1987, 1989, 1990; Addendum 2000, 2005.
  • Lawrie.
  • Sclatter, Thomas. 1894-1900.
  • Thomas 1891.
  • Trense 1989.
  • Walther 1958, 1960, 1963, 1968.
Glossary

Citation

Bauer, J. (2008). Dibatag. Retrieved from http://www.eoearth.org/view/article/151722

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