Death of the ‘Big Things’ of Australia

This has been interpreted as an effect of Aboriginal burning. I think it is better explained as a response to the sudden removal of large animals. Ecologists who analyse Australian vegetation today should reflect that it is in a bereft state, and try to re-imagine it in partnership with the continent’s ancient megafauna.

Of course, Europeans have put large mammals back into Australian landscapes - do they re-fill the ecological roles of the marsupial megafauna? In some cases, maybe. It is possible that feral camels in arid Australia browse the same plants in the same ways that the biggest megafauna once did. Perhaps we should be grateful to them. On the other hand, the concentrated grazing and soil compaction inflicted by sheep seem totally new and destructive pressures.

The second reason that this matters is that we still have a lesson to learn from it. Megafauna are typically resilient to environmental pressures and are great survivors in the natural world, but they are demographically highly sensitive even to very small increases in mortality imposed by people. Interaction with people has almost invariably led to their extinction, in Australia and elsewhere.

The new frontier of human-megafauna interaction is in the oceans, where whales, dugongs and some large fish are the demographic analogues of extinct megafauna on land. The lesson of the past is that hunting of large slow-breeding animals like these has extinction as its common endpoint. We should not do it.