Evidence suggests that there will be another major climatic change in the future. In the past, species and ecological communities could adapt by shifting along environmental gradients, but today that would present a problem for many species because there are so many artificial barriers like cleared farmland and cities. Now that we know the general reasons for marsupial endangerment and extinction, let us concentrate on one species, Phascolarctos cinereus , and examine the dangers it faces. Many people outside Australia have the idea that the country is heavily populated with koalas, but most Australians have never even seen a koala in the wild-only in zoos. No one really knows exactly how many koalas remain because of their secretive, nocturnal behavior.
Humans are their principal predator.
With the arrival of Europeans, it became widely known how easily koalas could be caught because of their characteristic slowness. Millions were hunted and killed for their fur. When it became known that some 500,000 koala furs were being sent to St. Louis every year, the U.S. public responded with outrage and disgust. As demand gradually died down, most of the hunting stopped. The last open season for koala hunting was in 1927.