PARIS -- As much as a fifth of the species of wildlife in Southeast Asia will go the way of the dodo by the end of the century because of catastrophic habitat loss, scientists warn.

The estimate is based on an unprecedented study into the state of flora and fauna in Singapore.

Over the past 183 years, between 34 and 87 percent of species of butterflies, fish, birds and mammals that were native to Singapore have disappeared.

The extinction rate among plants, amphibians, reptiles, stick insects and their relatives and local species of crabs is between five and 80 percent.

The cause, the authors say, is ruthless deforestation and untrammeled human expansion, a problem that is also chronic in Indonesia, Malaysia, Vietnam, Thailand and other countries in Southeast Asia.

"Since the British first established a presence in Singapore in 1819, more than 95 percent of the estimated 540 square kilometers (216 sq. miles) of original vegetation cover has been entirely cleared," the study says. "Less than 10 percent of the remaining 24 sq. km. (9.6 sq. miles) of remaining forest is primary (the majority being secondary regrowth)."

It means that forest reserves comprising only 0.25 percent of Singapore's area now harbor over 50 percent of the remaining native biodiversity.

"The current unprecedented rate of habitat destruction in Southeast Asia will result in the lost 13-42 percent of regional populations over the next century," the study says.

"At least half" of these losses will entail species that exist nowhere else. The study, led by Barry Brook of Northern Territory University in Darwin, Australia, appears in Thursday's issue of the British weekly Nature.