One third of 'extinct' animals back from the dead: Study

A new study has found that one-third of all mammal species declared extinct in the past few centuries have turned up alive and well.

Some of the more reclusive creatures managed to hide from sight for 80 years only to reappear within four years of being officially named extinct in the wild.

The shy okapi — which resembles a cross between a zebra and a giraffe — was first discovered in the Democratic Republic of Congo in 1901.

After repeated rare sightings, it vanished from the wildlife radar for decades from 1959, prompting fears that it had died out.

But five years ago researchers working for the World Wide Fund for Nature (WWF) found okapi tracks in the wild.

Other mammals believed to have become extinct and later rediscovered include the rat-like Cuban solenodon, the Christmas Island shrew, the Vanikoro flying fox of the Solomon Islands, the Australian central rock rat, and the Talaud flying fox of Indonesia.

Diana Fisher of the University of Queensland compiled a list of all mammals declared extinct since the 16th century or which were flagged as missing in scientific papers.

"We identified 187 mammal species that have been missing since 1500," The Daily Mail quoted her as writing in the journal Proceedings of the Royal Society B.

"In the complete data-set, 67 species that were once missing have been rediscovered. More than a third of mammal species that have been classified as extinct or possibly extinct, or flagged as missing, have been rediscovered," she wrote.

Though the new report has not played down the threat from deforestation, over-fishing or habitat destruction, it has raised questions about the way species are classified as extinct.