London: Big mammals including the elephant, rhinoceros and hippopotamus could vanish within the next 100 years as smaller creatures, able to adapt to more confined habitats, flourish.

Researchers at Southampton University found that the body mass of mammals will collectively reduce by 25 per cent over the next century as humans further encroach on to their land.

Hippos might not survive as habitat shrinks. Credit: Justin McManus

Although most of the reduction will be caused by the extinction of large animals, some bigger creatures may actually shrink in size as they are forced to deal with smaller habitats.

Experts studied nearly 15,500 mammals and birds and used computer modelling to predict how expected habitat loss would affect populations.