Nanger dama

Geographic Range

Gazella dama inhabits the countries of the African Sahel and Sahara Desert. At one time, the range of this mammal extended as far as Morocco and Egypt. However, excessive hunting has reduced their range to only the area between Senegal (where it was re-introduced) and Sudan.

• Biogeographic Regions
• palearctic palearctic
  • native native
• ethiopian ethiopian
  • native native

Habitat

Generally, Gazella dama is found in arid areas with sparse vegetation. However, its habitat changes slightly throughout the year, as this animal migrates seasonally. Dama gazelles resides on the pastures and plateaus of the Sahara desert during the rainy season, and move to the open bushlands in the dry season. This species avoids the mountains and dunes of the region, instead opting for the flatter, stonier plains. Unfortunately, due to overgrazing by livestock, land development by humans, and long term climate change, the habitat of G. dama has become even drier and somewhat less suitable through the years.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• desert or dune desert or dune
• savanna or grassland savanna or grassland

Physical Description

Nanger dama has a body with lean legs and a long slender neck. Its glossy coat is characterized by patches of reddish-brown and white. Its face and undersides are always white, its neck is reddish-brown, and its throat always bares a white patch. However, color varies between sub-species. Nanger dama mohrr , the western sub-species, is almost completely red, excluding its undersides and posterior. It also boasts red cheek patches and black stripes which trace from its eyes to the corner of its mouth. The eastern sub-species, Nanger dama ruficollis is mostly white, with its reddish-brown color only showing on its neck and back.

These animals possess horns that are shaped like the letter S; they point back and curl upwards. The horns generally range from 25 to 35 cm in length, with males possessing slightly larger sets than females. They are also sexually dimorphic in size, with females usually weighing 35 to 40 kg, and males ranging anywhere from 40 to 75 kg in weight.

Their basal metabolic rate is relatively high given their body size, as is often the case for members of Artiodactyla .

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger
• ornamentation ornamentation

Reproduction

The mating season can begin as early as August and end as late as October. During this time, males become territorial and engage in behaviors that indicate their aggressiveness and status. They usually urinate or defecate to mark their territory and horn the grass to advertise their strength and high status. Males also herd and chase to keep females in their vicinities and other rival males away.

The courtship behaviors of males usually include prancing, nose-lifting, upright posture, kicking of their forelegs, and touching, nibbling, or licking of the female with their muzzles. Some males may even resort to sputtering or snoring to get the attention of a mate.

A receptive female often walks in circles, makes sharp turns, and holds out her tail to indicate that she is ready to mate. The male mounts by standing behind her on his hind legs, with his forelegs curled in toward his own body. It is common for the female to continue moving during copulation.

• Mating System
• polygynous polygynous
• cooperative breeder cooperative breeder

Mating generally occurs between the months of August and October, although it has been known to occur year-round in captivity. The estrous cycle of female G. dama usually lasts about 19 days, although it can be as short as 16 days or as long as 22 days.

Generally, this species gives birth to one offspring at a time, although in rare circumstances, twins are born.

Immediately after birth, mothers keep newborns sequestered from the rest of the herd. After a few days, however, the young are usually strong enough to follow their mothers around the grasslands and be seen by other members of the herd.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• viviparous viviparous

The mothers of this species invest lots of energy in protecting their young. It is quite common for two females to team up in defending their offspring, as pairs of females can often be observed chasing and attacking jackals that are hunting young gazelles.

• Parental Investment
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • protecting
    • female
• post-independence association with parents

Lifespan/Longevity

In the wild, members of G. dama generally live up to 12 years. In captivity, they have been known to live into their late teens (18-19).

Behavior

Gazella dama is generally a social animal, living in herds. A hierarchy exists in the small, mixed-sex groups of this species, with the dominant male marking his status by either standing apart from the rest of the herd, or by horning the bushes and grasses. Males often use their horns to make threats, engaging in head shaking and 'pretend' fights in order to display their strength.

• Key Behaviors
• cursorial
• terricolous
• diurnal diurnal
• motile motile
• migratory migratory
• territorial territorial
• social social
• colonial colonial
• dominance hierarchies dominance hierarchies

Home Range

These animals make long seasonal migrations, moving into the Sahara Desert during the rainy season, and out into the open bushlands during the dry season. When in the desert, they live together in groups as large as several hundred, although in the bushlands, they usually congregate in groups of about 10 to 20 individuals. Many groups consist of a dominant male, several females, and several young, although maternal herds (only females and their young), and bachelor herds (only males) have been observed.

Communication and Perception

Most communication in this species is through body language. For example, erect posture in males demonstrates aggressiveness and high rank, and is also used in sexual displays. Males may also angle their heads or ram bushes so as to draw attention to their horns. Submission, on the other hand, is often represented by lowering of the head, or by jutting of the chin. Turning or moving away are also employed as ways to indicate submission. These animals utilize scent as well, as all members of a tribe urinate and defecate as a way of marking their territory against outsiders. Males have been known to snort or sputter during sexual displays.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• pheromones pheromones
• scent marks scent marks

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Gazella dama is a grazer, feeding on shrubs, herbs, coarse desert grasses, and Acacia tree leaves. These gazelles often stand on their hind legs in a bipedal fashion in order to reach the higher leaves of these trees. Members of this species are able to get most of the water they need from the plants they eat.

• Primary Diet
• herbivore herbivore
  • folivore folivore

• Plant Foods
• leaves

Predation

Gazella dama has many predators, including jackals, cheetahs, spotted hyenas, and lions. Fleeing is their main defense, and they are well adapted for running.

When a Dama gazelle spots a predator, it assumes an alert posture, and often stamps its feet, walks in circles, twitches its flank skin, and snorts in order to warn other members of the tribe.

Ecosystem Roles

Gazella dama controls the spread of Acacia trees by grazing on their leaves. These gazelles are also a source of food for many of the carnivores that live and hunt on the plains.

Economic Importance for Humans: Positive

Humans hunt gazelles for their meat and horns.

• Positive Impacts
• food food
• body parts are source of valuable material

Economic Importance for Humans: Negative

Grazing by G. dama can take food away from livestock, negatively impacting humans involved in the business of raising animals.

Conservation Status

This species was declared vulnerable by the IUCN in 1986, and was later shifted to endangered status in 1990. The continuous decline of G. dama numbers has been attributed to hunting and habitat degradation caused by humans.

Currently, there are efforts in Senegal to increase the Dama gazelle population through semi-captive breedings programs.

Other Comments

Dama gazelles were previously recognized under the name Gazella dama .

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Lisa Villarreal (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor.

References

Antelope Specialist Group 1996, 2004. "2004 IUCN Red List of Threatened Species" (On-line). Accessed March 22, 2006 at http://www.redlist.org/search/details.php?species=8968 .

Atkins, W. 2003. Gazella dama. Pp. 48 & 57 in Grzimerk's Animal Life Encyclopedia , Vol. 16, 2nd Edition. Detroit: Thomson Gale.

Engel, H. 2005. "Gazella Dama" (On-line). Accessed January 31, 2006 at http://www.kbinirsnb.be/cb/antelopes/Aridlands%20Antelopes/fiche%20dama%20description.pdf. .

Estes, R. 1993. The Safari Companion . Post Mills, Vermont: Chelsea Green Publishing Company.

Lovegrove, B. 2000. The Zoogeography of Mammalian Basal Metabolic Rate. The American Naturalist , 156: 201-219.

Massicot, P. 2004. "Animal Info - Dama Gazelle" (On-line). Accessed January 31, 2006 at www.animalinfo.org/species/artiperi/gazedama.htm .

Pickard, A., T. Abaigar, D. Green, W. Holt, M. Cano. 2001. Hormonal characterization of the reproductive cycle and pregnancy in the female Mohor gazelle (Gazella dama mhorr). Reproduction , 122: 571-580.

Walther, F. 1990. Gazelles and related species. Pp. 462-463 in Grzimek's Enyclopedia , Vol. 5, 1 Edition. New York: McGraw-Hill.

Ybanez, M., M. Goyena, T. Abaigar, M. Garijo, C. Martinez-Carrasco. 2004. Periparturient increase in faecal egg counts in a captive population of mohor gazelle (Gazella dama mhorr). The Veterinary Record , 154: 49-52.

Microsoft. 2006. "Sahara" (On-line). Encarta. Accessed March 02, 2006 at http://uk.encarta.msn.com/encyclopedia_761560427/Sahara.html .