Many people credit the demise of large animals living during the last glaciation as due to the effect of the warming of the climate. Their extinction also coincides with with the first appearance of humans in many areas, particularly in North and South America. As humans always prefer to hunt the larger animals first, (more meat available for least energy expenditure), it seems more likely that they were hunted to extinction due to their inability to recognize humans as predators. Large animals in areas previously inhabited by Homo sapiens lasted much longer as they already knew them to be dangerous and would avoid them, if possible. This also applies to Australian mega-fauna, (giant wombats and kangaroos), which started to disappear at the same time as people first arrived on that continent.