Nanger 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. (Atkins, 2003; Massicot, 2004; Walther, 1990)
Generally, Nanger 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 N. dama has become even drier and somewhat less suitable through the years. (Atkins, 2003; Massicot, 2004; "Sahara", 2006; Walther, 1990)
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. (Atkins, 2003; Engel, 2005; Estes, 1993; Lovegrove, 2000; Massicot, 2004; Walther, 1990)
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. (Estes, 1993; Massicot, 2004; Walther, 1990)
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 N. 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. (Massicot, 2004; Pickard, et al., 2001; Walther, 1990; Ybanez, et al., 2004)
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. (Estes, 1993)
Nanger 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. (Atkins, 2003; Estes, 1993; Walther, 1990)
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. (Atkins, 2003; Estes, 1993; Walther, 1990)
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. (Estes, 1993)
Nanger 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. (Atkins, 2003; Massicot, 2004; Atkins, 2003; Massicot, 2004; Atkins, 2003; Massicot, 2004; Atkins, 2003; Massicot, 2004)
Nanger 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. (Estes, 1993; Walther, 1990)
Nanger 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. (Atkins, 2003; Estes, 1993; Massicot, 2004; Walther, 1990; Atkins, 2003; Estes, 1993; Massicot, 2004; Walther, 1990; Atkins, 2003; Estes, 1993; Massicot, 2004; Walther, 1990)
Humans hunt gazelles for their meat and horns. (Walther, 1990)
This species was declared vulnerable by the IUCN in 1986, and was later shifted to endangered status in 1990. The continuous decline of N. dama numbers has been attributed to hunting and habitat degradation caused by humans.
Dama gazelles were previously recognized under the name Gazella dama.
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.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
uses sound to communicate
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.
helpers provide assistance in raising young that are not their own
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
union of egg and spermatozoan
an animal that mainly eats leaves.
A substance that provides both nutrients and energy to a living thing.
An animal that eats mainly plants or parts of plants.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
makes seasonal movements between breeding and wintering grounds
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
chemicals released into air or water that are detected by and responded to by other animals of the same species
having more than one female as a mate at one time
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.
associates with others of its species; forms social groups.
uses touch to communicate
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5? N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
breeding takes place throughout the year
Microsoft. 2006. "Sahara" (On-line). Encarta. Accessed March 02, 2006 at http://uk.encarta.msn.com/encyclopedia_761560427/Sahara.html.
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 M Hutchins, ed. 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 S Parker, ed. 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.