Competition for grazing threatens rare zebra speciesJune 21st, 2012 by Helen Vesperini in Biology / Ecology
A lone Grevy's Zebra graze at the foot of the Matthews Range at the West Gate conservancy near Kenya's Samburu national reserve. The saucer-shaped ears and barcode-tight stripes of the black-and-white animals set Grevy's zebras apart from ordinary zebra.
Five zebras roam the dusty Naibelibeli plains of this protected wildlife area in Kenya as a dozen camels, bathed in afternoon sunlight, feed on thorn trees.
The saucer-shaped ears and barcode-tight stripes of the black-and-white animals set them apart from ordinary zebra. These are Grevy's zebra, a separate species whose numbers have plummeted in recent years.
Habitat loss driven by human population growth, hunting and disease mean fewer than 2,500 remain, down from about 15,000 at the end of the 1970s.
"People are settling everywhere and grazing everywhere," said Peter Lalampaa, a Samburu tribesman and senior manager at the Grevy's Zebra Trust, who was visiting West Gate.
"Schools are mushrooming around here and pastoralists who used to move around are settling down, so overgrazing is becoming an issue."
The animal's range once stretched into Somalia, Djibouti and Eritrea, but is now limited to the arid lands of northern Kenya and one pocket of Ethiopia.
Lalampaa's group and the Kenya Wildlife Service say herds of up to 500 Grevy's zebra roam here, but on a visit this month the largest group had just five members.
The Grevy's cousin, the plains zebra, is much more common, with a population of about 660,000, according to the last study a decade ago. Their range extends from the southernmost parts of South Sudan and Ethiopia down into South Africa.
Until Kenya banned trophy hunting in 1977, Grevy's zebra were shot for their skin. Hunting for meat probably had an even more dramatic impact on their numbers.
The Grevy's zebra, unlike the plains zebra, which needs to drink daily, can go without water for five days, but recent dry spells have taken their toll.
With drought comes anthrax. Experts say that in parched times it's often impossible to tell whether an animal has succumbed to the drought or to the disease.
Kenyan wildlife officials in 2006 carried out a mass anthrax vaccination of the zebras, which got their name after one was gifted to French president Jules Grevy in the late 19th century.
Some northern tribes, such as the Turkana, still consider the meat a delicacy. For others such as the Samburu, whose men wear brightly coloured blankets and whose women sport a wide collar of red beads, eating meat from a member of the horse family is taboo.
Kenya outlawed the sale of game meat in 2004 in a bid to rein in poaching.
In this community conservancy, with its acacia trees and rocky outcrops at the base of the Matthews Range, competition for the limited grazing space is fierce.
"Young boys would kill the foals in their games and chase away the zebras to keep pasture for their animals," explained Muriankan Lalampaa, a young Samburu herder from a tiny mud-hut settlement that the villagers share with their goats, donkeys and camels.
Kenya has one of the world's highest population growth rates and pressures on wildlife are likely to remain. But attitudes towards the Grevy's zebra are changing, says Muriankan, partly because of the start of community tourism initiatives.
"Now people no longer chase them away," he said.
One reason is that locals, including several women from Muriankan's settlement, are now employed by the zebra trust to monitor the animals.
George Anyona, Grevy's zebra liaison officer at the Kenya Wildlife Service, says human-wildlife conflicts result from a lack of planning and not a lack of land.
"If we plan well we will still have enough space," he said, indicating the vast expanse of the plains. "I would love my grandchildren one day to also see the Grevy's zebra."
"Otherwise we will have to tell them we used to have Grevy's zebras and we finished them off."
(c) 2012 AFP
"Competition for grazing threatens rare zebra species." June 21st, 2012. http://phys.org/news/2012-06-competition-grazing-threatens-rare-zebra.html