Gazella dorcasdorcas gazelle

Last updated:

Geographic Range

Gazella dorcas is found in the northern Ethiopian biogeographic region and the southwestern Palearctic region. These gazelles inhabit parts of northern Africa, and the Sahara and Negev deserts including: Morocco, Rio de Oro, Algeria, Tunisia, Libya, Chad, Somalia, Ethiopia and parts of Israel and Sinai in the Middle East. (Yom-Tov, et al., 1995)

Habitat

Gazella dorcas is the best equipped member of the genus Gazella to inhabit dry areas. They are found in a variety of habitats: savannahs, semi-deserts, small sand dune fields, consolidated dune areas, and wadis, and are associated with a number of different plant species. High densities of G. dorcas are found in sand dune fields with high concentrations of Pancratium sickenbergeri, a preferred food. (Lawes and Nanni, 1993; Ward and Saltz, 1994; Yom-Tov, et al., 1995)

Physical Description

Gazella dorcas varies in coloration, depending on the location. They are generally pale colored and have a white underbelly with two brown stripes on either side. In the northern Sahara they are an ochre color with darker flanking stripes. Near the Red Sea, they are reddish-brown with less conspicuous, light flanking stripes. The head is darker than the rest of the body. Their horns have the most pronounced curve of members of Gazella, and within the subspecies the amount of curve in the horn varies. Horns of males are 250-280 mm long and have 20-24 rings. Female's horns are smaller (170-190 mm) and straighter with 16-18 rings. Adult males average 16.5 kg, while the females are about 12.6 kg, although average size varies among populations. They are the second smallest gazelle species. (Yom-Tov, et al., 1995)

  • Range mass
    14 to 18 kg
    30.84 to 39.65 lb
  • Average mass
    16.5 kg
    36.34 lb

Reproduction

During the September to November mating season males will guard territory marked by their droppings. Depending on local climate, a group of G. dorcas will consist of one or two males with a harem of females or just a male-female pair. In extreme climates, where resources are scarce, they primarily associate in pairs. (Yom-Tov, et al., 1995)

In the wild, females will usually begin reproducing around age two. In captivity pregnancy can happen as early as six months of age. About 90% of females in the wild became pregnant. They give birth to only one offspring per pregnancy in almost all cases. Pregnancy lasts around six months and the fawn is born with hair and open eyes. Young spend the majority of their first two weeks curled up in the shade. Afterwards they will follow the mother around looking for solid food. Males do not seem to participate in the care of the young, except indirectly through resource defense for the group. (Ward and Saltz, 1994; Yom-Tov, et al., 1995)

  • Breeding interval
    Breeding occurs once yearly.
  • Breeding season
    Breeding occurs from September to November.
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    6 months
  • Average gestation period
    182 days
    AnAge
  • Average weaning age
    3 months
  • Range time to independence
    1 (low) years
  • Average age at sexual or reproductive maturity (female)
    2 years
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    730 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    589 days
    AnAge

Females nurse their young for one to two minutes several times a day for around 3 months. For the first two weeks of the young gazelle's life, the mother grazes and sleeps away from the young gazelle, leaving it in a safe spot. As the young gazelle grows, they join their natal group for the first year, or longer. (Yom-Tov, et al., 1995)

  • Parental Investment
  • precocial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

In captivity Gazella dorcas can live up to 15 years. Average lifespan in the wild is unknown and may vary by population. (Yom-Tov, et al., 1995)

Behavior

Activity patterns are determined by the severity of the climate. In hot summers these gazelles are mostly active at dawn and dusk. In milder temperatures they can be active all day. They may also become nocturnal when under predation pressure from diurnal predators. Depending on the climate, G. dorcas can travel in pairs or larger groups consisting of one or two males with a harem of up to four females and their young. Sometimes males will travel in bachelor groups of four or five. (Ward and Saltz, 1994; Yom-Tov, et al., 1995)

  • Average territory size
    25 km^2

Home Range

Home range of a male accompanied by a small group of females and young is about 25 square kilometers. (Yom-Tov, et al., 1995)

Communication and Perception

Gazelles have an alarm call which sounds like a short bark. They also use a louder call made in cases of extreme danger or pain. Females have a low grunt to call the young and all G. dorcas can produce a long growling sound that signals annoyance. When in danger from a predator, "stotting", described in the predation section, is a common way to warn other gazelles of the predators presence. (Yom-Tov, et al., 1995)

Food Habits

Gazella dorcas individuals feed on the flowers, leaves, and pods of Acacia trees in many of the areas they inhabit. They also feed on fruits and leaves of a variety of bushes. In the Negev Desert, G. dorcas feeds on Madonna lilies (Pancratium sickenbergeri). Depending on the season, methods for obtaining food change. In summer gazelles dig holes in the sand to remove the stem and bulb of Madonna lilies. After winter rains, gazelles eat freshly sprouted leaves. Foraging techniques permit maximum energy intake with minimum energy output. Large amounts of feeding are done in small areas with high concentrations of plant life followed by long moves to other feeding areas. (Lawes and Nanni, 1993; Ward and Saltz, 1994; Yom-Tov, et al., 1995)

  • Plant Foods
  • leaves
  • roots and tubers
  • wood, bark, or stems
  • seeds, grains, and nuts
  • fruit
  • flowers

Predation

Gazella dorcas populations have many predators. Cheetahs, lions, servals, caracals, wolves, and hyaena prey on all sizes and ages. Young can be killed by smaller predators, such as foxes, eagles, and jackals. Many of these predators have been wiped out in areas where gazelles are currently found. Humans, wolves and caracal continue to be major predatory threats to these gazelles. Gazella dorcas relies chiefly on its keen eyesight to watch for predators. They have calls described in the communication section that help alert others in a herd to the presence of a predator. Skin shivering, tail twitching, and taking bouncing leaps with its head high, also called stotting, are all used to warn others of the presence of a predator. (Ward and Saltz, 1994; Yom-Tov, et al., 1995)

Ecosystem Roles

Gazella dorcas, along with some other ungulates, make up the primary mode of seed dispersal for a variety of plants in the Acacia genus between the Red Sea and Israel. (Lawes and Nanni, 1993; Ward and Saltz, 1994; Yom-Tov, et al., 1995)

  • Ecosystem Impact
  • disperses seeds
Mutualist Species
  • Acacia

Economic Importance for Humans: Positive

Gazella dorcas is hunted as a food source. (Yom-Tov, et al., 1995)

  • Positive Impacts
  • food

Economic Importance for Humans: Negative

Gazella dorcas is better adapted for the environment around Israel in the Negev desert than other grazing animals. They outcompete other grazers such as sheep and goats that are used for economic purposes. (Yom-Tov, et al., 1995)

Conservation Status

This species is considered threatened and in the past was classified as vulnerable by the IUCN. The ongoing threats to this species are habitat destruction and illegal hunting. (Yom-Tov, et al., 1995)

Other Comments

Gazella dorcas individuals can go their entire lives without drinking water. They can get all the water they need from the plants they eat. There is a high mortality rate among young born in captivity because of inadequate resistance to infection. (Yom-Tov, et al., 1995)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Joshua Stoolman (author), Kalamazoo College, Ann Fraser (editor, instructor), Kalamazoo College.

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

crepuscular

active at dawn and dusk

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.

folivore

an animal that mainly eats leaves.

food

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

frugivore

an animal that mainly eats fruit

granivore

an animal that mainly eats seeds

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).

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.

nocturnal

active during the night

nomadic

generally wanders from place to place, usually within a well-defined range.

polygynous

having more than one female as a mate at one time

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

threatened

The term is used in the 1994 IUCN Red List of Threatened Animals to refer collectively to species categorized as Endangered (E), Vulnerable (V), Rare (R), Indeterminate (I), or Insufficiently Known (K) and in the 1996 IUCN Red List of Threatened Animals to refer collectively to species categorized as Critically Endangered (CR), Endangered (EN), or Vulnerable (VU).

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.

young precocial

young are relatively well-developed when born

References

Lawes, M., R. Nanni. 1993. The density, habitat use and social organisation of dorcas Gazelles (Gazella dorcas) in Makhtesh Ramon, Negev Desert, Israel. Journal of Arid Environments, 24: 177-196.

Ward, D., D. Saltz. 1994. Foraging at different spacial scales: dorcas gazelles foraging for lilies in the negev desert. Ecology, 75: 48-58.

Yom-Tov, Y., H. Mendelssohn, C. Groves. 1995. Gazella dorcas. Mammalian Species, 491: 1-6.