The kangaroo population in Australia has exploded since European farming methods were introduced. This is mainly because European technologies for clearing land and replacing it with grazing fields were highly effective. Kangaroos, and wombats for that matter, are grazing animals, and compete with Sheep and Cattle for the grass.
The Native American Indians and Aboriginals did not have the mastery of metallurgy as the Eurasians and Central Americans did. Their forest clearing method, and consequently their animal husbandry technology, was fire.
Charles Mann writes in 1491:
Rather than domesticate animals for meat, Indians retooled ecosystems to encourage elk, deer, and bear. Constant burning of undergrowth increased the numbers of herbivores, the predators that fed on them, and the people who ate them both.Mann recounts the original settlers in Ohio being able to drive carriages through the trees like in English Parks. Rather than the thick over-grown, impenetrable and entangled forest of mythical lore, it was an open woodland with little undergrowth. Mann continues:
A creature of the prairie, Bison was imported to the East by Native Americans along a path of indigenous fire, as they changed enough forest into fallows for it to survive far outside its original range.That migratory highway is the American Great Plains and Mid-west. One of the largest human-scaped ecosystems. I had not previously made the connection between a pre-metallurgical society's use of fire and animal husbandry on an ecological level of scale. It makes perfect sense in Australia as well. Burning the bush off removes the undergrowth and provides greater grassland for grazing animals such as the Kangaroo - a staple of the Aboriginal diet. The main issue for the Aboriginal people, and probably why there isn't a Great Plain in Australia, was the eucalypt tree. What a remarkably adaptive species which lives in desert, in snow, on the salt stained coast, and in rainforests. I have even seen them used for landscaping on the Arizonan Sonora Plain. In terms of fire for increasing grassland, the eucalypt can take being burnt off, and come back strongly soon after. Which isn't news, every Australian has been amazed at how quickly the eucalypts recover from a bushfire.
