Koala numbers crashed across Australia 100,000 years ago. Global glacial cycles are likely to blame

It's surprising how easy it is to see a koala every day in Australia's major cities.

The cute, gray marsupial can be found on T-shirts, hanging off people's bags and pencils, and decorating any decent souvenir shop.

But seeing a real koala in the wild has become increasingly tricky in some parts of the country.

The iconic marsupial is now listed as endangered in Queensland, New South Wales and the Australian Capital Territory. ...