Facts on Elephants in NamibiaNovember 14, 2012
The amazing anaboom – a vital sourceNovember 14, 2012
A HORSE-LIKE DONKEY OR A DONKEY-LIKE HORSE?
The origin of the word zebra is not certain. It probably comes from an African language via Portuguese (zevra). The Damara word for zebra is !oareb and the Oshiwambo word ongolo.
There are only three species of zebra extant – the plains zebra, including the Burchell’s zebra found in Etosha; the mountain zebra, including Hartmann’s mountain zebra found in north-western Namibia; and the more distantly related Grévy’s zebra found in Kenya and Ethiopia. While the Grévy’s species is more akin to a donkey, the other species look more like domestic horses. All three belong to the horse family Equidae.
There are about 13 000 zebras in the Etosha National Park. They are unfortunately particularly susceptible to the deadly disease anthrax, which causes several hundred to perish in the park each year.
WHY THE STRIPES?
Zebras are very social animals. They live in groups ranging from small ‘harem’ groups dominated by a stallion, to large herds. A zebra’s stripes are basically vertical around its fore quarters, but horizontal around its rump. Each animal’s stripes are different, and as individually characteristic as fingerprints on a human. The purpose of the stripes is not known.
The most obvious explanation is camouflage, especially when the stripes are brown and black (plains zebra) rather than white and black (mountain zebra). Another theory is that the striped pattern somehow confuses the visual system of the blood-sucking tsetse fly, which finds it difficult to ‘navigate’ to the host. However, if this is why zebra have them, you might wonder why other animals haven’t tried the same trick.
Then there is the perhaps philosophical question as to whether the zebra is a white animal with black stripes, or a black animal with white stripes.
NOT SUITABLE FOR DOMESTICATION
As one might expect, attempts have been made to domesticate and ride zebras. This has not been very successful, due mainly to the zebra’s nervous and unpredictable temperament. However, the legendary millionaire Lord Rothschild imported four to London and used them to draw his carriage through the streets.
THE EXTINCT QUAGGA
The quagga was a subspecies of zebra, once plentiful in South Africa, which was hunted to extinction sometime in the 1870s. In the London Zoo there are photographs of them, as well as several stuffed specimens. The quagga had stripes only around its head and neck. Its back and hindquarters were plain brown, and its legs were white. Perhaps because it rather resembled a cross between a zebra and horse, some researchers were led to suspect that it was not a distinct species, and that quagga genes might still survive in some modern zebra populations. This led to the controversial but interesting quagga reclamation project, where zebras with suspected quagga traits are being interbred to try and bring the long extinct quagga back to life!
WHAT IS A ZORSE AND WHAT IS A ZEBRULE?
Although zebras and domestic horses are similar in shape and belong to the same family, they are genetically quite different. Horses have 64 chromosomes and zebras between 32 and 40. This means that zebras and horses do not readily interbreed, but should this happen, it is usually between a zebra stallion and a mare. The result is a strange, partially striped animal called a zebroid, zorse, zedonk or zebrule. Because of their genetic incompatibility these hybrids are always sterile, like a mule, and are not of much practical use. However, zebroids, zorses, zedonks, zebrules and quagga are incredibly useful and extant words for players of Scrabble.
Sources and references available from firstname.lastname@example.org
This post formed part of the monthly “Did you know”column written by Bill Torbitt for Flamingo magazine. It originally appeared in the November 2012 issue.