Elephants, hippos and rhinos face extinction within 100 years as humans destroy habitats
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 25pc over the next century as humans further encroach on to their land.
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.
While creatures like the Asian elephant, Javan rhinoceros and giraffe will struggle with habitat loss, animals expected to flourish include the brown rat, bush rat and blackbird, which are more adaptable.
Rob Cooke, lead author of the study published in the journal 'Nature Communications', said: "By far the biggest threat to birds and mammals is humans - with habitats being destroyed due to deforestation, hunting, intensive farming, urbanisation and the effects of global warming.
"In the future, small, fast-lived, highly fertile insect-eating animals that can thrive in a wide variety of habitats, will predominate."