Kangaroos....and a bit on Koalas!!!!

The native animals that survived the ecosystem collapse were those that humans found difficult to hunt. The Kangaroo was one such animal. Although it congregates in groups, unlike a sheep or cow, the Kangaroo is not a herd animal. If a mob of Kangaroos is attacked, individuals run in different directions which makes them difficult to kill on mass. Humans soon adapted by using fire in hunting. With fire, a mob of Kangaroos could be herded towards a group of people waiting with spears. Unfortunately, the use of fire further contributed to the drying of Australia and continued the expansion of the desert. Eventually, eucalyptus forests, which recover quickly from fire damage, were all that remained in Australia. Koalas aside, eucalypts are not suitable for large browsing animals. A bountiful land of rainforests and large animals had become a land of desert, eucalyptus and small animals adept at avoiding humans.

http://www.convictcreations.com/aborigines/megafauna.html