Elephant family group in Samburu, Kenya. Credit: Iain Douglas-Hamilton.

(PhysOrg.com) -- Half the elephants from West and Central African savannahs have vanished in the past 40 years, scientists report in PLoS One.

A team, including Iain Douglas-Hamilton of Oxford Universitys Department of Zoology, estimate that around 7,750 elephants remain in the Sudano-Sahelian zone, which covers 20% of the continent, a 50% decline in four decades.

Of the 23 elephant populations studied half are now thought to number less than 200 animals and so are unlikely to survive. The survey covered protected areas so populations in unprotected regions are likely to have fared even worse.

A reduction in rainfall and increasing competition with humans for land and water resources used for livestock and agriculture are, the researchers believe, the main factors behind the decline. Warfare and the illegal trade in ivory have also helped to drive some elephant populations to the brink of extinction.

The loss of these elephant populations would affect many other species which rely on the habitat created by these giant herbivores as they browse, clear the brush and disperse seeds.

To protect the remaining animals the researchers propose that eight new protective corridors be established as soon as possible to connect the main elephant populations.

They also recommend working with private sector wildlife initiatives and channelling more wildlife revenues to local communities as a way of securing the future for elephants on Africas northern savannahs.

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