SciDi: Koalas – Strategies
Music; Ambience: Male Koala growling
JM: We’re listening to the sounds of a male koala. Welcome to Pulse of the Planet’s Science Diaries, a glimpse of the world of science from the inside. Koalas have been described as the most boring animal on earth, because they’ll just sit in a tree all day, seemingly doing nothing. According to biologist Alistair Melzer, the koala is inactive in the daytime for a very good reason.
AM: “They’re staying cool, staying calm. But, now we can start to see that the koalas are making decisions about how they live in a landscape, and using that landscape to help them keep their metabolic rate very low.”
JM: The koala’s favorite food are eucalyptus leaves. But it takes a lot of energy to digest them.
AM: “You have to understand that koalas eat a type of vegetation that is highly indigestible, lots of fiber, and includes a lot of toxic compounds. The koalas spend a lot of time doing nothing, putting all their energy into digesting this fibrous material.”
JM: On the island where Alistair Melzer conducts his research, he’s noticed that the koalas have adapted two strategies for conserving their energy.
AM: “During the night, they go out into the eucalypt trees to feed. Then during the day they come back, and they often select a dense rainforest shrub to sit in. But some koalas have adopted a completely different strategy. Instead of using a rainforest shrub during the day for shelter, they traveled some distance to a rainforest gully and they stayed there during the day. So there’s some level of complexity in there which we’ve never been aware of before.”
JM: To hear more about Alistair Melzer’s research with koalas, check out his blog on pulseplanet.com. Pulse of the Planet’s Science Diaries are made possible by the National Science Foundation. I’m Jim Metzner.