Barcelona, Oct. 6 (AFP): Half the world’s mammals are declining in population and more than a third probably face extinction, according to an update of the Red List, the most respected inventory of global bio-diversity.

A study by the International Union Conservation of Nature (IUCN) found that a quarter of the planet’s 5,487 known mammals are clearly at a risk of disappearing forever. But the actual situation may be grimmer as researchers have been unable to classify the threat level for another 836 mammals because of lack of data.

“In reality, the number of threatened mammals could be as high as 36 per cent,” IUCN scientist Jan Schipper, lead author of the mammal survey, said in the US journal Science.