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Animal Info - Grevy's Zebra
(Other Names: 格雷维(细纹)斑马,
格利威斑馬, グレビーシマウマ,
Cebra de Grévy, Grande zebra do Grévi, Grevyzebra,
Imperial Zebra, Punda Milia Somali,
Zèbre de Grévy)
Equus grevyi
Contents
1. Profile (Picture)
2. Tidbits
3. Status and Trends (IUCN Status, Countries Where
Currently Found, Population Estimates, History of Distribution, Threats and Reasons
for Decline)
4. Data on Biology and Ecology (Weight, Habitat, Age to Maturity, Gestation
Period, Birth Season, Birth Rate, Early Development, Maximum Age, Diet, Behavior, Social
Organization, Density and Range)
5. References
Profile
Pictures: Grevy's
Zebra #1 (49 Kb JPEG); Grevy's
Zebra #2 (Huffman 2004)
Grevy's zebra weighs 350 - 450 kg (770 - 990 lb). It lives in arid, open bushed
grassland and is adapted to survive droughts, as long as it can reach water every several
days. Grasses make up about 70% of the Grevy's zebra's diet. It also browses on shrubs and
trees. The Grevy's zebra has an open society in which females with their young and males
on established territories are the focal points.
There are no permanent bonds between adults. They are solitary or live in a variety of
different associations that usually do not last longer than a few months. Some stallions
are territorial, with territories of up to 12
sq km (4.6 sq mi). The resident stallion tolerates other stallions in his territory, but
they do not interfere with the resident stallion when he is mating.
The Grevy's zebra formerly occurred from central Ethiopia
to Somalia and northern Kenya. It experienced a significant decline in the
1970's, apparently due to poaching to obtain the zebra's attractive hide for fashion. It
is now found only in northeastern Ethiopia and
some reserves in Kenya.
Poaching of Grevy's zebra is no longer a threat, due to protection under CITES. Loss of grazing habitat and access to water, due
to competition with increasing herds of domestic livestock, is the primary threat to the
Grevy's zebra. Additional threats are due to reduced river flow, due to irrigation, and
uncontrolled tourism in reserves, which causes disturbance and destruction of vegetation.
Tidbits
*** The distribution of Grevy's zebra is "wedged" between the ranges of
arid-adapted [African] wild ass and water-loving common zebra. (Kingdon 1997)
*** A young Grevy's zebra can walk within a half hour of birth and can run for short
distances within 45 minutes of birth.
*** The Grevy's zebra is the largest of the wild equids.
Status and Trends
Countries Where the Grevy's Zebra Is Currently Found:
2004: Occurs in Ethiopia and Kenya. May occur in Sudan.
(IUCN 2004)
Population Estimates:
[Note: Figures given are for wild populations only.]
History of Distribution:
In the past, the Grevy's zebra was found in the Awash Valley, the Ogaden region, and
northeast of Lake Turkana in Ethiopia, south into
Kenya east of the Rift Valley and Lake Turkana,
north of Mount Kenya and the Tana River, and east into western Somalia. It apparently experienced a significant
decline in the 1970's. In the late 1980's it occurred in three isolated populations: Kenya, north of the Tana River; Ethiopia, on the east side of Omo River to Lake
Zwai, and Somalia. It has not been seen in Somalia since 1973 and is presumed to be extinct
there. It is now restricted to Ethiopia and Kenya, and possibly Sudan.
Most Grevy's zebras surviving in Ethiopia are in
the northeast of Lake Turkana, the Alledeghi plains; the Yabello Sanctuary and around Lake
Chew Bahar. In Kenya, Grevy's Zebra occurs in much
of its former range; east of the Rift Valley and Lake Turkana, north of Mount Kenya and
the Tana River, and east towards western Somalia. (WCMC/WWF 1997)
Distribution
Map #1 (31 Kb GIF) (IUCN/SSC Eq.
Spec. Gr. 2004)
Distribution
Map #2
(14 Kb JPEG) (African Mammals
Databank 2004)
Threats and Reasons for Decline:
Poaching of Grevy's zebra skins for use in fashion was a major problem during the
1970's, especially until 1976, when Kenya passed protection laws. Poaching is no longer a
threat, due to protection under CITES. Loss of
grazing habitat and access to water, due to competition with increasing herds of domestic
livestock, is the primary threat to the Grevy's zebra. In addition, reduced river flow,
due to irrigation, has decreased the availability of surface water in parts of its Kenyan
range. In reserves, another threat results from uncontrolled tourism, which causes
disturbance and destruction of vegetation.
Data on Biology and Ecology
The female Grevy's zebra weighs 350 - 400 kg (avg 385 kg) (770 - 880 lb (avg 847 lb));
males weigh 380 - 450 kg (avg 430 kg) (836 - 990 lb (avg 950 lb)).
Habitat:
Grevy's zebra lives in semi-arid bush/grass mosaics with a preference for tracts of
grassland growing on deep sand, hard-pans, sumplands and in areas where fire and elephants
have degraded the dominant Acacia/Commiphora woodlands. (Kingdon 1997) It is able to live in deserts
if there is permanent water within reach every 2 - 5 days (for lactating mares 1 - 2 days)
(van Dierendonck & de Vries
1996).
Grevy's zebra lives in both the Horn
of Africa Biodiversity
Hotspot (Cons.
Intl. 2005) as well as the Horn of Africa Deserts Global 200 Ecoregion. (Olson & Dinerstein 1998, Olson & Dinerstein 1999)
Age to Maturity:
Close to 6 years (wild); 3 - 5 years (captivity).
390 - 400 days.
Birth Season:
Usually August or September, but mating and births can occur all during the year.
Birth Rate:
A mare usually bears 1 young at a time. There are usually 2 years between births.
Early Development:
Young are generally weaned at about 8 - 13
months of age.
Maximum Age:
Up to 18 years in the wild.
Diet:
Grasses make up about 70% of the Grevy's zebra's diet. It also browses on shrubs and
trees.
Behavior:
Female Grevy's zebras return to localized birthing areas that appear to be traditional.
Social Organization:
The Grevy's zebra has an open society in which females with their young and males on
established territories are the focal points.
There are no permanent bonds between adults. Females associate in nursing groups, males in
bachelor groups and all classes may join up in large, mixed herds, with none of these
groupings lasting longer than a few months. Aggression is infrequent except that territorial males assert their mating
prerogatives. A solitary breeding stallion maintains a large territory and associates with
mares only when they enter his territory. The most successful males win grassy territories
close to water. Grass and water are major attractions, especially for lactating females.
Density and Range:
Some stallions are territorial. The territories are large for a herbivore: 2.7 - 10.5 sq km (1 - 4 sq mi) in
northern Kenya (Nowak & Paradiso 1983).
The territories of the breeding males are
the largest that have been found in any ungulate
(Duncan 1992).
Individual long-term ranges of both females and males can cover up to 10,000
sq km (4000 sq mi) (Duncan 1992). Males have territories of up to 12 sq km (4.6 sq
mi) (Kingdon 1997).
References
African Mammals Databank
2004,
Arkive,
AZA 1994, Burton
& Pearson 1987, Cons.
Intl. 2005, Duncan 1992, Eliot 1993, Huffman
2004, IUCN 1994, IUCN 1996,
IUCN 2000, IUCN
2003a, IUCN
2004, IUCN/SSC Eq. Spec. Gr.
2004, Kingdon
1997, Macdonald 1984, Nowak & Paradiso 1983, Olson & Dinerstein 1998, Olson & Dinerstein 1999, Oryx 1977d, Oryx
1980e, Oryx 1981c, Schuhmacher 1967, Shefferly
1996, Stuart & Struart 1996, van Dierendonck & de Vries 1996, WCMC/WWF 1997
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