for National Geographic News
The elephants live in Mali, in the Gourma region of the Sahel, an ever-narrowing strip of land that lies between the desert in the north and the savanna in the south. The Sahel in West Africa is a near-desert wasteland of sparsely vegetated plains and endless miles of sand dunes.
To survive in this extremely harsh landscape, each year the Gourma elephants follow a circular migration path that covers 450 kilometers (280 miles), moving from one water hole to the next. No other group of elephants is known to follow such a pattern. View an interactive map of the elephants' ancient highway, as tracked by radio collars and the satellites.
"The elephants must travel long distances between water holes, sometimes as far as 100 to 150 kilometers (62 to 93 miles) in a day or two," said Iain Douglas-Hamilton, a conservation biologist with Save the Elephants. "They have to move far and fast without water, and they do it mostly at night."
The circular migration route is arduous, with varied terrain and a punishing climate. Many of the water holes dry up quickly after the end of a very short rainy season. An error in judgmentarriving at a spot with no water, for instancecould lead to the death of the herd.
Add growing human populations, decreasing rainfall, creeping desertification, and changing land use patterns, and the survival prospects for the last Sahelian elephants look grim.
As recently as 30 years ago, large herds of elephants ranged throughout West Africa, from the forests along the coastline to the very edge of the Sahara. Poaching, human encroachment, and environmental degradation have drastically reduced their numbers.
Today, elephant populations in West Africa are smallmore than half consist of fewer than 100 individuals. The herds are geographically isolated and their remaining habitat is highly fragmented.
The 325 to 350 elephants in the Gourma region of Mali is one of West Africa's largest populations. Researchers with Save the Elephants, a non-profit research organization conducting elephant studies in Kenya, South Africa, and Congo, as well as Mali, were able to pinpoint the elephant's numbers and migration corridors using GPS technology.
"The whole technology applied to elephants is something we've been pioneering," said Douglas-Hamilton. "It allows us to track the day-to-day movements of individual elephants and actually reconstruct the lives of the elephants in a way that has never been done before."
Led by a matriarch, female elephants and their young travel an average of six miles (ten kilometers) a day, "up and down mountains, in and out of forests, deserts, savannas, across remote places," said Douglas-Hamilton. Bull elephants travel independently and meet up with the rest of the herd around Banzena, the region's most reliable water source, from March to May.
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