October 2012

Koalas: An Australian Treasure

A small, volcanic island may hold the secret to preserving these iconic creatures...

Koalas are quite fond of just "hanging around".
"Do you mind?" Koalas usually spend most of the day dozing off.
Alistair Melzner and an Earthwatch volunteer prepare the koala tracking equipment on St. Bees Island.
A scenic view from St. Bees Island in Australia.



Koala bears may resemble cute, cuddly, sleepy-eyed teddy bears but in reality they're rather cantankerous, shy and elusive - not to mention having a formidable set of claws and a bellow that will send shivers down your spine. They're not even bears! Despite not exactly living up to their warm and fuzzy stereotype, koalas are among a few unique and fascinating creatures native to Australia.

If you're lucky enough to spot one, you will probably find it dozing off for an afternoon tree-nap. Koalas are generally inactive during the day and use most of this time to digest their preferred food – eucalyptus leaves. The female is smaller than the male, which can grow reach between 15-30lbs. Koalas belong to the marsupial family, meaning their young are carried in a pouch for the first stage of their lives. The only close koala relative is a burrowing creature that resembles a large, stocky rodent called a wombat.

Sadly, koala numbers have slipped drastically over the past 20 years dropping 40 per cent in Queensland and a third in New South Wales. In April 2012, the koalas in these regions were added to Australia's vulnerable species list but it will take more than a listing to save the dwindling colonies. Scientists and biologists have identified many factors contributing to their decline such as habitat destruction, malnutrition and disease but there does not seem to any "fix-all" solution in sight. Meanwhile, in southern regions like Victoria, koalas have managed to reproduce to the point of over-exploiting their already sparse habitats.

Why are southern koalas multiplying so quickly while the eastern populations are being devastated? Alistair Melzer, a biologist with the University of Central Queensland, is trying to shed some light on this riddle. Since 1998, Melzer along with colleagues and volunteers, has actively been studying a population of koalas, which has managed to remain relatively stable.

St. Bees Island is a quiet, volcanic isle fringed with reefs, rainforests, eucalypt woodlands and dense grasslands located off the coast of Mackay in North Queensland, Australia. In the 1930s, a resort on St. Bees decided to "import" a small number of koalas from the nearby Australian mainland in an effort to enhance tourism. They seem to have actually done the koalas a favor. Although the resort has been gone for decades, the koalas have made themselves at home. The koala population on St Bees has have grown slowly and remained stable. Now, roughly 300 koalas inhabit the island. Professor Melzer sees the island as "a living laboratory in which to study what keeps an isolated population in balance", while he searches for answers to managing overpopulated habitats elsewhere in Australia".

Stay tuned to Pulse of the Planet in the month of October as Alistair tracks koalas on St. Bees Island.

You can read Alistair's Science Diary blog by visiting: www.pulseplanet.com/sci-diaries/sd_melzer

To see the official listing and read the koala's fact sheet, visit: www.environment.gov.au/biodiversity/threatened/species/koala.html