according to Australian media
Koalas 'extinct within 30 years' after chlamydia outbreak - Telegraph
A conservation group has warned that overdevelopment, disease, climate change, and sexual disease are killing off the species.
The Australian Koala Foundation has urged the government to list the species as vulnerable after it found there may be as few as 43,000 of the tree-dwelling animals left on the mainland.
The figures show that koala populations have fallen sharply since the last survey in 2003, when it was estimated that there were 100,000 in Australia.
A study carried out by the foundation earlier this year found that since then the mainland population had fallen to between 43,000 and 80,000.
If the rate of "drastic decline" continued unchecked, the koala could vanish in 30 years, the group warned.
The foundation said its research confirmed years of anecdotal reports of dwindling populations along the east coast.
"I think it will be very hard for anyone to walk away from this data.
We have a very high level of confidence that it accurately shows a drastic decline," said the foundation's chief executive, Deborah Tabart.
Large numbers have been killed by an outbreak of chlamydia, a sexually transmitted disease, while others have been affected by loss of habitat due to deforestation and climate change, she said.
Hotter, drier conditions had also reduced the nutritional value of their staple food, eucalyptus leaves, leading to fatal malnutrition.
The Koala Foundation collected data from 1,800 field sites and 80,000 specific trees in an attempt to gauge koala numbers.
But in one area of northern Queensland state which had an estimated 20,000 koalas a decade ago, a team of eight people did not find even one koala after four days of recent searching, Ms Tabart said.
Koalas live in eucalyptus forests in Australia's east and south, and are notoriously fussy about what types of eucalyptus leaves they eat.
It is estimated that the furry marsupials generate $1 billion a year to the Australian economy in tourism.
An attempt in 2006 to have the species listed as vulnerable failed when the federal government's threatened species steering committee decided it did not meet the criteria