A group of conservationists and researchers from Cornell University have proposed the introduction of African wildlife (including lions, cheetahs, elephants, and camels) to the North American Great Plains region. The scientists suggest that such a step would help maintain rapidly dwindling populations of the endangered animals. Additionally the African 'megafauna' could step into ecological roles vacated by now extinct Pleistocene-period creatures that once inhabited North America.

Find out more:

• Cornell conservationists propose allowing wild animals to roam parts of North America (Cornell University)
• Lions, elephants to roam the US plains? (National Geographic)
• Big game 'could roam US plains' (BBC News)
• Lions and elephants on the Great Plains? (CNN)