There are three species of zebras: the plains zebra, the
Grévy's zebra and the mountain zebra. The plains zebra and the mountain zebra
belong to the subgenus Hippotigris, but Grévy's zebra is the sole species of
subgenus Dolichohippus. The latter resembles an ass, to which it is closely
related, while the former two are more horse-like. All three belong to the
genus Equus, along with other living equids. The.The unique stripes of zebras make
them one of the animals most familiar to people. They occur in a variety of
habitats, such as grasslands, savannas, woodlands, thorny scrublands,
mountains, and coastal hills. However, various anthropogenic factors have had a
severe impact on zebra populations, in particular hunting for skins and habitat
destruction.
Grévy's zebra and the mountain zebra are endangered. While plains
zebras are much more plentiful, one subspecies, the quagga, became extinct in
the late 19th century – though there is currently a plan, called the Quagga
Project, that aims to breed zebras that are phenotypically similar to the
quagga in a process called breeding back.The name "zebra" in English
dates back to c.1600, from Italian zebra, perhaps from Portuguese, which in
turn is said to be Congolese (as stated in the Oxford English Dictionary). The
Encarta Dictionary says its ultimate origin is uncertain, but perhaps it may
come from Latin equiferus meaning "wild horse"; from equus
("horse") and ferus ("wild, untamed"). The word was
traditionally pronounced with a long initial vowel, but over the course of the
twentieth century, the pronunciation with the short initial vowel became the
usual one in the UK and Commonwealth.
Zebras evolved among the Old World horses
within the last 4 million years. Grévy's zebras (and perhaps also Mountain
Zebras) are, together with asses and donkeys, in a separate lineage from other
zebra lineages. This means either that striped equids evolved more than once,
or that common ancestors of zebras and asses were striped and only zebras
retained the stripes.The mountain zebra (Equus zebra) of southwest Africa tends
to have a sleek coat with a white belly and narrower stripes than the plains
Zebra. It has two subspecies and is classified as vulnerable.Although zebra
species may have overlapping ranges, they do not interbreed. In captivity,
plains zebras have been crossed with mountain zebras. The hybrid foals lacked a
dewlap and resembled the plains zebra apart from their larger ears and their
hindquarters pattern. Attempts to breed a Grévy's zebra stallion to mountain
zebra mares resulted in a high rate of miscarriage.
In captivity, crosses
between zebras and other (non-zebra) equines have produced several distinct
hybrids, including the zebroid, zeedonk, zony, and zorse. In certain regions of
Kenya, plains zebras and Grévy's Zebra coexist, and fertile hybrids occur.The
common plains zebra is about 50–52 inches (12.2–13 hands, 1.3 m) at the
shoulder with a body ranging from 6–8.5 feet (2–2.6 m) long with an 18-inch
(0.5 m) tail. It can weigh up to 770 pounds (350 kg), males being slightly
bigger than females. Grévy's Zebra is considerably larger, while the mountain
zebra is somewhat smaller.Zebras have excellent eyesight. It is believed that
they can see in color.[citation needed] Like most ungulates, the zebra has its
eyes on the sides of its head, giving it a wide field of view. Zebras also have
night vision, although not as advanced as that of most of their predators.
Like
most members of the horse family, zebras are highly social. Their social
structure, however, depends on the species. Mountain zebras and plains zebras
live in groups, known as 'harems', consisting of one stallion with up to six
mares and their foals. Bachelor males either live alone or with groups of other
bachelors until they are old enough to challenge a breeding stallion. When
attacked by packs of hyenas or wild dogs a zebra group will huddle together
with the foals in the middle while the stallion tries to ward them off.Zebras
feed almost entirely on grasses, but may occasionally eat shrubs, herbs, twigs,
leaves and bark. Their digestive systems allow them to subsist on diets of
lower nutritional quality than that necessary for other herbivores.
Female
zebras mature earlier than the males, and a mare may have her first foal by the
age of three. Males are not able to breed until the age of five or six. Mares
may give birth to one foal every twelve months. She nurses the foal for up to a
year. Like horses, zebras are able to stand, walk and suckle shortly after they
are born. A zebra foal is brown and white instead of black and white at
birth.Zebra are a popular subject in art. The fourth Mughal emperor Jahangir
(r.1605–24), commissioned a painting of the zebra, which was completed by Ustad
Mansur. Zebra stripes are also a popular style for furniture, carpets and fashion.The
Cape mountain zebra was hunted to near extinction, with less than 100
individuals by the 1930s. The population has since increased to about 700 due
to conservation efforts. Both mountain zebra subspecies are currently protected
in national parks, but are still endangered.

No comments:
Post a Comment