Study estimates pre-colonial Indigenous Australian population at 2.2 million

The authors wrote that historical population estimates had been poor "due to lethal diseases, frontier and structural violence, and absence of systematic censuses", and that correcting them was "invaluable to truth-telling and reconciliation". They warned readers that the content of the study is confronting and possibly distressing.

Co-author Corey Bradshaw, a professor of global ecology at Flinders University, said the modelling implied millions of excess deaths from smallpox and other diseases, massacres, dispossession and malnutrition. His earlier research found that an 1789 smallpox outbreak alone killed as many as 220,000 Aboriginal people. Further smallpox epidemics followed, along with outbreaks of measles, influenza, tuberculosis and typhoid.

Bradshaw said he would bet his career that massacre databases were underestimated by an "order of magnitude". "If you're a frontier farmer, a colonialist that came out to a new area, and you were trying to remove people from 'your' land, you're not going to write extensively about how many people you killed to do that," he said. He added that greed and racism were a further factor: "the entire concept of terra nullius was based on not many people being here. If there's a systematic desire to take land [fewer people means a] better justification for imperialism."

Australia was colonised on the basis of terra nullius, the doctrine that the land belonged to no one, which was overturned by the high court's Mabo decision recognising that First Nations people had been on the continent for tens of thousands of years. Aboriginal and Torres Strait Islander people were not properly counted in the census until 1971, after the 1967 referendum, when 115,953 people identified as Aboriginal and/or Torres Strait Islander. In 2021, 812,728 were counted, a figure revised upwards to 983,257 after post-census recounts.

Earlier estimates varied widely. Governor Arthur Phillip put the Gadigal people of the Eora nation at about 1,500. The first continent-wide estimate, by the social anthropologist Alfred Radcliffe-Brown, was between 250,000 and 300,000, drawn mainly from observations made after the effects of colonisation had been felt; Radcliffe-Brown knew it was an underestimate, but many researchers used it as a baseline. In 1983 the economic historian Noel Butlin estimated about 900,000, later raising the figure to between 1.1 million and 1.3 million. In 1987 the archaeologists John Mulvaney and J. Peter White argued it was more likely 750,000.

The team used several approaches: archaeological items to reconstruct how many people were present at particular times, reconstructions of climate and the productivity of the land to infer how many people it could sustain, and genetic data worked back in time using known DNA mutation rates. They reviewed ethnographic estimates but did not rely on them.

"We are not talking about a marginal consequence of colonisation but a demographic catastrophe at the heart of the Australian story," said Larissa Behrendt, a Euahleyai/Gamillaroi woman who chairs the CIEHF's advisory committee.

Co-author Lynette Russell, of Monash University's Indigenous Studies Centre and the CIEHF, said the findings highlighted the scale of the demographic catastrophe experienced by Indigenous Australians, with implications for a heightened understanding of intergenerational trauma and for informing future policy that assists Indigenous people. The authors wrote that Australia must prioritise reconciliation, engagement and policymaking.

Editor's Summary

The study estimates Australia's Indigenous population at 2.2 million before 1788 and 2.06 million excess deaths between 1788 and 1861, leaving about 7% of the original population. It attributes the scale of loss to disease, massacres, dispossession and malnutrition, and argues that earlier figures of around 250,000 were derived largely from observations made after colonisation had already taken effect.