Dama gazelle

This article is about the gazelle. For other uses, see Dama (disambiguation).
Dama gazelle
N. d. mhorr
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Antilopinae
Genus: Nanger
Species: N. dama
Binomial name
Nanger dama
(Pallas, 1766)
Subspecies
  • N. dama dama (dama)[2]
  • N. dama mhorr (mhorr)
  • N. dama ruficollis (addra)

also see text

Geographic range
Synonyms
  • Gazella dama

The dama gazelle, addra gazelle, or mhorr gazelle (Nanger dama, formerly Gazella dama) is a species of gazelle. It lives in Africa in the Sahara desert and the Sahel. This critically endangered species has disappeared from most of its former range due to overhunting and habitat loss, and natural populations only remain in Chad, Mali, and Niger.[1] Its habitat includes grassland, shrubland, semi-deserts, open savanna and mountain plateaus.[1] Their diets includes grasses, leaves (especially Acacia leaves), shoots, and fruit.

In Niger, the dama has become a national symbol. Under the Hausa name meyna or ménas[3] the dama appears on the badge of the Niger national football team, who are popularly called the Ménas.[4][5]

Description

The dama gazelle is white with a tannish-brown head and neck. Both sexes usually have medium-length ringed horns curved like an "S". Males' horns are about 35 cm (14 in) long, while females' horns are much shorter. The gazelles' heads are small with narrow muzzles, their eyes are relatively large, and they have longer necks and legs than most gazelles. These animals are between 90 and 120 cm (35 and 47 in) tall at the shoulder,[6] weigh between 35 and 75 kg (77 and 165 lb), and have lifespans up to 12 years in the wild or 18 in captivity.[7] A few days following birth, dama young are strong enough to follow the herd, and after a week, they are able to run as fast as the adults.

Damas are considered the largest type of gazelle, with incredibly long legs, which provide extra surface area on their bodies to dissipate heat, one of the many ways they stay cool in their hot desert environment. They also tend to need more water than some of their desert relatives, but they can withstand fairly long periods of drought. Unlike many other desert mammals, damas are a diurnal species, meaning they are active during the day.

Always on the alert, damas use a behavior called pronking to warn herd members of danger. Pronking involves the animal hopping up and down with all four of their legs stiff, so their limbs all leave and touch the ground at the same time. Males also establish territories, and during breeding season, they actively exclude other mature males. They mark their territories with urine and dung piles and secretions from glands near their eyes.

Subspecies status and conservation

The dama gazelle is generally divided into three subspecies based on the colour of the animal's back, flanks and haunches.[8] These three subspecies occupied three blocks running along the east–west axis of the gazelle's range.[8] The easternmost is the N. dama ruficollis (common name addra gazelle) whose historical range was to the east of 15°E.[8] The westernmost is the N. dama mhorr (common name mohor or mhorr gazelle) whose historical range was to the west of 7°E. Between the two was the historical range of the N. dama dama.[8] Genetic studies have raised questions over the validity of these subspecies and the variation in colour (phenotype) appears to be clinal.[8]

The numbers of this species in the wild have fallen by 80% over the last decade.[1] The IUCN now lists it as critically endangered with a wild population of less than 500 (the most recent review suggests c. 300).[1][8] They occur in poor countries and little action is taken to protect the species; the national parks are not well guarded and poaching still occurs.[1] It has been extirpated from Libya, Mauritania, Morocco and Nigeria. Populations remain in Chad, Mali and Niger, and it has been reintroduced in Senegal and Tunisia.[1]

Ontogeny and Reproduction

Breeding takes place from March to June, and the young born around December.[10]

Ecology and Behavior

A diurnal species, this gazelle requires more water than others adapted to its dry habitat, although it can survive long periods of draught. Like most desert species, the dama gazelle is highly nomadic, ranging widely in order to obtain sufficient nutrition.[10] In addition, these gazelles undertake large seasonal migrations, moving north into the Sahara desert during the rainy season, and retreating south into the Sahel during the dry season. To maximize the amount of food available, these gazelles may stand on their hind legs in a manner reminiscent of the gerenuk in order to reach leaves above the normal browsing height. Adult males are believed to be territorial during the breeding season.[10]

Threats to survival

Biological threats

Dama gazelles do not need a lot of water, but they need more than other desert animals. They are not as resistant and perish from a lack of water during the drought season. The environment has become ill-suited for them. Habitat pressure from pastoral activity is another reason for decline, as are introduced diseases from livestock.[11]

Human threats

Another reason for the decline of this gazelle is habitat destruction. Humans cut down the branches of the trees on which these gazelles feed. As a result, the trees die and the gazelle cannot eat.[12]

Human threats are the most dangerous of threats to the dama gazelle. The main reason this species of gazelle is endangered is because of mechanized hunting; hunters using vehicles increase their decline.[12] Civil unrest, for instance in Sudan, also negatively affects the life of the dama gazelle.[12] Since the gazelle is already having a hard time surviving, these conditions have made its habitat unsuitable.[13]

A new threat the gazelle faces is tourism. Tourists want to take pictures of this endangered species, and in doing so, may be perceived as a threat, especially during the hot season.[12] Gazelles will run away from perceived danger, and in the hot season may overheat and die of stress.

Conservation efforts

Relatively few actions have been taken in the conservation of the dama gazelle.[1][11] The few measures that have been taken are reserves so the animal can live in peaceful environment and captive breeding to help rebuild the populations.

A reserve for mhorr gazelles was set up in 1971 to help avoid extinction. This reserve, Parque de Rescate de la Fauna Sahariana (Rescue Park for Saharan Fauna) of the Estación Experimental de Zonas Áridas (Experimental Station of Arid Zones), is in Spain. The reserve has been a success and is still around today.[14]

Another reserve for the mhorr subspecies was set up in Chad, the Ouadi Rime-Ouadi Achime Faunal Reserve.[12] This reserve was effective from 1978–1987, but due to civil war, it was abandoned.[11]

Captive breeding is a very popular way to help an endangered species repopulate. The species reproduce in captivity, but the small founder population potentially presents a problem and may result in inbreeding.[8][14] The primary focus of European EAZA zoos is the mhorr gazelle (N. d. mhorr), while the primary focus of North American AZA zoos is the addra gazelle (N. d. ruficollis). Mhorr gazelles are also kept in North African facilities and both subspecies are kept in the Middle East.[8] These are maintained as part of the European Endangered Species Programme and Species Survival Plan.[8] The studbooks include 293 mhorr (2014) and 168 addra gazelles (2012).[8] One participant in the addra gazelle plan, White Oak Conservation in Yulee, Florida, has bred the gazelles since 1983, resulting in nearly 300 births.[15] Several hundred additional animals that are not managed as part of the studbooks are kept privately, especially in Texas.[8]

Addra gazelles, part of the breeding program at the National Zoo in Washington, DC

Small population size and inbreeding are a serious concern in this population due to the increased parasite load and reduced reproductive viability.[16] Few substantial in situ conservation efforts have been mounted due to the political situation in their currently fragmented habitat. The survival of this species in the wild depends on more reserves being created in the Sahelian and Saharan zones and better protection in the reserves that do exist.[1][12] As the population deteriorates, researchers in 2008 stressed the need for healthy captive population and for help to preserve their habitats in the wild.[11]

Gallery

References

  1. 1 2 3 4 5 6 7 8 9 Newby, J., Wacher, T., Lamarque, F., Cuzin, F. & de Smet, K. (2008). "Gazella dama". IUCN Red List of Threatened Species. Version 2011.2. International Union for Conservation of Nature. Retrieved 11 May 2006. Database entry includes justification for why this species is critically endangered
  2. ↑ Nanger dama, MSW3
  3. ↑ Dama Gazelle Nanger dama. Sahara Conservation Fund, 2007, 2011.
  4. ↑ Orange 2012 Afcon qualifiers :130 Million FCFA for the Menas. 22/05/2011 StarAfrica sports.
  5. ↑ Menas to test Pharaohs form. Confederation of African Football. 10-09-2010
  6. ↑ Arkive Dama Gazelle
  7. ↑ Gazella Dama Historical Studbook, AZA, 2008
  8. 1 2 3 4 5 6 7 8 9 10 11 12 13 Senn, Helen; Banfield, Lisa; Wacher, Tim; Newby, John; Rabeil, Thomas; Kaden, Jennifer; Kitchener, Andrew C.; Abaigar, Teresa; Silva, Teresa Luísa; Maunder, Mike; Ogden, Rob (June 23, 2014). "Splitting or Lumping? A Conservation Dilemma Exemplified by the Critically Endangered Dama Gazelle (Nanger dama)". PLoS ONE 9 (6). doi:10.1371/journal.pone.0098693. Retrieved 9 September 2014.
  9. 1 2 Francois Lamarque, Amewey Ag Sid'Ahmed, Stephane Bouju, Gaoussou Coulibaly, Li, Daouda Maiga. (2007). "Confirmation of the survival of the Critically Endangered dama gazelle Gazella dama in south Tamesna, Mali". Oryx 41: 109–112. doi:10.1017/S0030605307001561.
  10. 1 2 3 4 5 6 ''Nanger dama'' Dama gazelle, An Ultimate Ungulate fact sheet. Ultimateungulate.com.
  11. 1 2 3 4 "Addra gazelle, Gazella dama ruficollis" (PDF). Retrieved 21 June 2013.
  12. 1 2 3 4 5 6 J.F. Grettenberger, J.E. Newby. (1986). "The Status and Ecology of the Dama Gazelle in the Air and Tenere National Nature Reserve, Niger". Biological Conservation 38 (3): 207–216. doi:10.1016/0006-3207(86)90121-7.
  13. ↑ Thompson A, Sudan’s migrating wildlife wows scientists. MSNBC, 2007.
  14. 1 2 F. Berlinguer, R. Gonzalez, S. Succu, A. del Olmo, J.J. Garde, G. Espeso, M. Gomendio, S. Ledda, and E.R.S. Roldan. (2008). "In vitro ooctye maturation, fertilization and culture after ovum pick-up in an endangered gazelle (Gazella dama mhorr)". Theriogenology 69 (3): 349–359. doi:10.1016/j.theriogenology.2007.10.001. PMID 18022681.
  15. ↑ "Addra Gazelle". Retrieved 21 June 2013.
  16. ↑ Jorge Cassinello, Montserrat Gomendio, Eduardo R.S. Roldan. (2001). "Relationship between coefficient of inbreeding and parasite burden in endangered gazelles". Conservation Biology 15 (4): 1171–1174. doi:10.1046/j.1523-1739.2001.0150041171.x.

External links

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