Nanger damadama gazelle

Geographic Range

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)

Habitat

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)

  • Range elevation
    760 (high) m
    2493.44 (high) ft

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. (Atkins, 2003; Engel, 2005; Estes, 1993; Lovegrove, 2000; Massicot, 2004; Walther, 1990)

  • Range mass
    35 to 75 kg
    77.09 to 165.20 lb
  • Range length
    140 to 168 cm
    55.12 to 66.14 in

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. (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)

  • Breeding interval
    Dama gazelles breed once a year.
  • Breeding season
    In the wild, mating usually occurs between the months of August and October.
  • Range number of offspring
    1 to 2
  • Average number of offspring
    1
  • Range gestation period
    5.5 to 6 months
  • Range weaning age
    3 to 4 months
  • Range age at sexual or reproductive maturity (female)
    1.5 to 2 years
  • Average age at sexual or reproductive maturity (male)
    1 years

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)

  • 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 N. dama generally live up to 12 years. In captivity, they have been known to live into their late teens (18-19). (Massicot, 2004)

  • Range lifespan
    Status: captivity
    19 (high) years
  • Typical lifespan
    Status: wild
    12 (high) years
  • Average lifespan
    Status: wild
    12 years

Behavior

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)

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. (Atkins, 2003; Estes, 1993; Walther, 1990)

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. (Estes, 1993)

Food Habits

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)

  • Plant Foods
  • leaves

Predation

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)

Ecosystem Roles

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)

Economic Importance for Humans: Positive

Humans hunt gazelles for their meat and horns. (Walther, 1990)

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

Economic Importance for Humans: Negative

Grazing by N. dama can take food away from livestock, negatively impacting humans involved in the business of raising animals. (Atkins, 2003; Massicot, 2004)

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 N. 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. (Antelope Specialist Group 1996, 2004; Massicot, 2004)

Other Comments

Dama gazelles were previously recognized under the name Gazella dama.

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.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

acoustic

uses sound to communicate

bilateral symmetry

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.

chemical

uses smells or other chemicals to communicate

colonial

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.

cooperative breeder

helpers provide assistance in raising young that are not their own

desert or dunes

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.

diurnal
  1. active during the day, 2. lasting for one day.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

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.

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

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).

migratory

makes seasonal movements between breeding and wintering grounds

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polygynous

having more than one female as a mate at one time

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sexual ornamentation

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.

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

terrestrial

Living on the ground.

territorial

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

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

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.

savanna

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.

temperate grassland

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.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

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.