An Australian researcher claims that the immigration of humans to Australia led to the extinction of several large species of herbivores:
Humans landed on the shores of Australia more than 45,000 years ago. The land they encountered was full of huge plant-eating animals, such as the 6,000-pound rhinoceros wombat and giant kangaroo. Sadly, things would soon change.
Soon after humans settled on Australia, some 55 giant animal species vanished from Australia, with various theories, from climate change to human hunting, put forth to explain the extinction.
Now, researchers have discovered that the arrival of these humans was likely the driver of intense changes to the region, which led to the annihilation of Australia's giant herbivores and drastic changes to the habitat that turned a patchy, shrub-filled landscape into a fire-prone grassy eucalyptus forest.