Elephants need to consume a minimum of 100 liters of water and 100 kilograms of vegetation daily, yet a small population of 350 manages to survive in the harsh Gourma region of Mali, south of the Niger River, where temperatures spike to 50˚C and vegetation is sparse.
The scientists published their findings in the journal Biological Conservation. Rainfall is also limited, with an annual accumulation of 110 mm in the north and 600 mm in the south. Researchers equipped GPS collars to nine of the animals, four females in four separate herds, and five randomly selected males. Their movements were tracked for two years.
The data revealed that the Gourma elephants traverse a vast home range of 32,000 square kilometers, the largest ever reported for elephants, in their search for food and water. The Gourma elephants’ range is 150% larger than ranges reported for desert elephants in Namibia.
The elephants follow a circular route through the desert, heading south at the beginning of the rainy season in April or May, and returning north later in the year, in the search of specific plants. The male and female elephants journeyed on such different routes that they only shared a quarter of their ranges. The Gourma elephants are believed to be the last of the herds that ranged across northern Africa and into the Atlas Mountains.
The findings could help conservationists, as the elephants face new pressures from climate change and human settlements.
Reference: “Characterizing properties and drivers of long distance movements by elephants (Loxodonta africana) in the Gourma, Mali” by Jake Wall, George Wittemyer, Brian Klinkenberg, Valerie LeMay and Iain Douglas-Hamilton, 27 November 2012, Biological Conservation.