11/13/2023 0 Comments Koala threats and predatorsNonetheless, European settlement in Australia from 1788 certainly had a massive impact on koala populations. Compared to kangaroos or possums, koala bones are scarce in the fossil record and they less commonly feature in pre-colonial Indigenous rock art or artifacts, despite their great cultural significance to many east and south coast Indigenous communities. This relative scarcity does not seem to be a recent phenomenon. (Image credit: Arthur Dorety/Getty Images) In the more inland arid forests, there may be as few as one koala found every 247 acres (100 hectares).Īustralia's megafauna started to vanish around 100,000 years ago, and koalas retreated to forests on the continent's eastern edges. Park managers typically consider three to four koalas per hectare the maximum sustainable number without risking forest damage, even in the most productive forests. This might put isolated populations at risk of extinction. Although koalas are a relatively widespread species, they are also extremely widely dispersed and rarely found in high densities. Species with small ranges are often more at risk of extinction. This was not the only time koala populations have crashed, nor the only time they have recovered. Genetic markers reveal that, around 30,000 to 40,000 years ago, koalas suffered from a catastrophic population crash, coinciding with the megafaunal extinctions around the world. The giant megafaunal cousins of the koalas, like the diprotodons, disappeared in this period and the koalas too retreated from the west and inland areas, and from most of South Australia. But as the climate began to dry around 100,000 years ago, the forests retreated towards the eastern edge of the continent. These forests, and their koalas, once stretched all the way across the south to the far west coast.
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