Monsters We Met - Man the hunter - page three

Australia

Animal survival in previous times of climate change

The Pleistocene was characterised by rapid shifts from warm (interglacial) to cold (glacial) climates and back again. Over the past 2.5 million years there have been 103 shifts in climate. Although there have been lots of extinctions over this time, the number of extinction events where large numbers of animals died out at once is tiny compared to the number of climate changes. Many animal genera came through several climate changes unscathed but then perished around the time of the final shift.

The human factor

Supporters of the overkill hypothesis point to a major difference between the last shifts in climate from warm to cold and back again. Human beings were spreading out of Africa and across the world during this period. Therefore megafauna had to cope with both a changing climate and a previously unencountered predator - humanity.

	The first people in Australia did not have stone spear points.

Stone, wood or bone

The first people in Australia did not have stone spear points - their spears were completely wooden or tipped with bone. Proponents of the overkill hypothesis say this is one reason why megafauna kill sites have not been identified in Australia - spear remains have long since rotted away in Australia's tropical climate. Opponents argue that even if the animals were killed with wooden spears, they would have been butchered with stone tools and so far no traces of cut marks on the bones have been found.

Cuddie springs

Cuddie Springs is in northern New South Wales. Excavations here have uncovered many bones from ten different megafauna species, including diprotodon and genyornis. Stone tools have also been found at Cuddie Springs, but it is difficult to tell if the tools were deposited at the same time as the megafauna. The sediments at the site have been jumbled together by a series of mudslides and slumps, making it very difficult to figure out the sequence of events.

Some of the tools from Cuddie Springs are said to be stained with animal blood and bits of tissue and hair. It has been speculated that this flesh and blood came from diprotodon. DNA analysis of the blood and of diprotodon bones was suggested as a method of proving this, but the results of the tests have not been published. The identity of the bloodstains on the tools remains a mystery.

New Zealand

	The ancestors of the Maori dumped the bones from the hundreds of moas they hunted.

Land of birds

New Zealand has been isolated from all other land masses for 80 million years. Both the dinosaurs and any primitive mammals that may have originally lived there have died out. Once the dinosaurs were gone, bird species evolved to fill the empty niches with many abandoning the energy-demanding flying lifestyle for life on the ground. Also filling traditionally mammalian roles are wetas, large wingless relatives of the grasshopper and locust, and stalking these are the tuataras - the only remaining species of a rhynchocephalid reptile.

Many of these unusual creatures became endangered or extinct after the arrival of people.

Archaeological evidence of hunting

There is no denying that overkill happened in New Zealand, starting about 800 years ago. There are large midden sites, where the ancestors of the Maori dumped the bones from the hundreds of moas they hunted. The hunting was so intensive that the moas had all perished some 100 to 400 years after humans first arrived. There were no large climate changes in New Zealand over this period of time.