Studying a Koala Mystery in Eastern Australia

Wallabies are also plentiful on St. Bees Island.

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One of the best places in the world to learn about koalas is St. Bees Island off the coast of Queensland in eastern Australia.

Decades ago, koalas were imported there to enhance tourism at a local resort.

The resort is long gone, but the koalas stayed, and their presence has led to a new kind of visitor: research biologists such as Alistair Melzer.

Melzer is studying the island's koalas, trying to understand why the iconic animal is thriving there, while on the verge of extinction in many other parts of Australia.

As so often happens in science, one question is answered, only to reveal another question. What is keeping St. Bees koalas in check is that sub-adults — that is, young koalas who are not yet independent — are disappearing. Why they are disappearing is still a mystery that Melzer is trying to solve.

Along the way, the biologist has learned some surprising facts about koalas, including how they are able to conserve their energy, which is crucial for their survival.

A koala expends 90 percent of its energy in digesting eucalyptus leaves, which are toxic for most other species.

So koalas need to minimize their energy output, which they do by finding shade and keeping their metabolic rate low.

For the past 18 months, independent radio producer Jim Metzner has been giving recording equipment to scientists and asking them to document their work in their own words. This report on Melzer's work is the first in an occasional series called Science Diaries.

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