The updated Red List, compiled by the International Union for the Conservation of Nature (IUCN), also warned that African grey parrots were facing extinction because they were being trapped so often for the pet trade.

More than 700 newly recognised bird species have also been assessed for the new update with more than one in 10 found to be at risk of dying out.

IUCN director general Inger Anderson said: "Many species are slipping away before we can even describe them.

"This IUCN Red List update shows that the scale of the global extinction crisis may be even greater than we thought."

There are now 85,604 species assessed for the Red List, of which more than a quarter - 24,307 - are threatened with extinction, being classed as critically endangered, endangered or vulnerable.