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.