Tuesday, Oct. 09, 2007
Global Warming: Bad News for Gnus
By Jumana Farouky/London
The annual wildebeest migration is one of nature's most spectacular photo-ops. More than a million wildebeest — also known as gnus — crossing from the Serengeti in Tanzania to Kenya's Masai Mara National Reserve and then back again in the search of fresh grass makes for some dramatic action shots, as massive herds travel across the plains before plunging into the Mara River to swim to greener pastures.
The photos from this year's migration are just as dramatic, but for a different reason. This time, piles of wildebeest carcasses line the riverbanks, after 10,000 of the animals drowned trying to cross the Mara at the start of their journey back east to the Serengeti. The deaths are natural: each year, crocodiles and the strong current claim some victims. The numbers, though, are bizarre. The migration rarely leaves more than a few thousand dead; but this year, an estimated 100,000, or about 1% of the wildebeest population, were wiped out. Conservationists say the wildebeest simply chose the wrong point to cross the river, one where the bank on the other side was too steep to climb. As those in the front drowned, they trapped those behind them.
Nature can be cruel, but sometimes it gets some help. The Mara River was especially high this year, after the heavy rains that flooded parts of Africa, killing hundreds of people and uprooting thousands more. Climatologists are pointing to the downpours as proof that predictions that Africa will suffer the most from global warming and climate change are already coming true. The human toll is what makes all the headlines, but the consequences for Africa's wildlife is just as drastic.
"During the rainy season, we should be getting mild rain spread over a long time and the dry season should be reasonably mild, not too hot," says Taye Teferi, head of the Conservation Program at the WWF's East Africa Regional Program Office. "But climate change has accentuated the difference between the seasons, making the rainy season shorter and heavier and the dry season hotter." When animals migrate to the Masai Mara every spring, it allows the vegetation they leave behind in the Serengeti to regrow, ready for them to come back in the fall. No rain means no new vegetation to return to. The animals stay put and the land can't cope: the grass stops growing, the animals die. And if it rains too much, "the water, which should be a source of rejuvenation, instead becomes a force of destruction," says Teferi...
http://www.time.com/time/health/article/0,8599,1669552,00.html