Zebra
Zebras (members of the horse family), are native to central and
southern Africa. They are black with white vertical stripes[1]
on the head, neck, forequarters, and main body, usually with horizontal stripes
at the rear and on the legs of the animal. The zebra crossing is named after the
zebra's white on black striping.
Originally, most zoologists assumed that the stripes acted as a camouflage
mechanism, while others believed them to play a role in social interactions,
with slight variations of the pattern allowing the animals to distinguish
between individuals. A more recent theory, supported by experiment, posits that
the disruptive coloration is an effective means of confusing the visual system
of the blood-sucking tsetse fly.
A zebra can travel at a top speed of fifty-five kilometres per hour, slower
than a horse. However, it has much greater stamina. During the course of a day
the plains zebra can walk around forty kilometres (from its herd, and back again
in the evening)
Species
There are four extant species, as well as several subspecies. Zebra
populations vary a great deal, and the relationships between and the taxonomic
status of several of the subspecies are unclear.
The Plains Zebra (Equus quagga, formerly Equus burchelli) is
the most common, and has or had about five subspecies distributed across much of
southern and eastern Africa. It, or particular subspecies of it, have also been
known as the Common Zebra, the Dauw, Burchell's Zebra (actually the subspecies
Equus quagga burchelli), and the Quagga (another, extinct, subspecies,
Equus quagga quagga).
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 endangered.
Grevy's Zebra (Equus grevyi) is the largest type, with an erect mane,
and a long, narrow head making it appear rather mule-like. It is an inhabitant
of the semi-arid grasslands of Ethiopia, Somalia, and northern Kenya. The
Grevy's Zebra is one of the rarest species of zebra around today, and is
classified as endangered.
Zebra classification
- Plains Zebra, Equus quagga
- Quagga, Equus quagga quagga (extinct)
- Burchell's Zebra, Equus quagga burchellii
- Grant's Zebra, Equus quagga boehmi
- Selous' zebra, Equus quagga borensis
- Chapman's Zebra, Equus quagga chapmani
- Crawshay's Zebra, Equus quagga crawshayi
- Cape Mountain Zebra, Equus zebra
- Hartmann's Mountain Zebra, Equus hartmannae
- Grevy's Zebra, Equus grevyi
|
