Australia had a much larger Indigenous population before the arrival of Europeans than previously thought, and that population suffered losses of 93 per cent after colonisation, according to new research.
The research, announced Tuesday, demonstrates much larger population losses resulting from colonisation than previously believed, with an estimated 93 per cent of the pre-European population removed in less than 80 years following the 1788 arrival of the First Fleet.
Professor Corey Bradshaw, Flinders University Global Ecology Professor and a Chief Investigator in the Australian Research Council Centre of Excellence for Indigenous and Environmental Histories and Futures (CIEHF), is part of a national research group working with Indigenous partners to investigate Indigenous population sizes through time.
Using sophisticated computer modelling they calculated that the Indigenous population was up to seven times larger than previously estimated.
"Understanding the size of Indigenous populations in Australia before European invasion in 1788 is essential to truth-telling and reconciliation," Professor Bradshaw said.
The research team arrived at new population estimates through reviewing ethnographic observations, archaeological and genetic reconstructions, and modelling environmental carrying capacity across the continent to estimate the Indigenous population size before colonisation.
Many previous estimates are anchored by one of the earliest attempts at determining pre-colonisation populations by anthropologist Alfred Radcliffe-Brown in the 1930s, who calculated a population of 250,000 people.
However, he acknowledged these values did not account for the impacts of lethal diseases, and frontier and structural violence. Increasingly, these impacts have been shown to be far more extensive than previously known and suggest that early figures underestimate the number of people across Australia.
Using modelled and genetics-based estimates (supported by, but not relying on, historical or ethnographic accounts), the researchers calculated a median pre-colonial Indigenous population of 2.22 million, or 0.29 people per square kilometre.
This compares with previous historical estimates of only 250,000-1,000,000 people, which the researchers say are underestimates due to the far-reaching impacts of disease, and frontier and structural violence that had affected populations by the time of early Australian censuses.
The new estimate also allows calculation of the number of excess deaths in the post-1788 era. To align with early census records, the model estimates 2.06 million excess deaths (an average of about 28,200 per year) occurred between 1788 and 1861.
These estimates show that by 1861, only about 7seven per cent of the estimated pre-colonial population survived.
"These devastating findings highlight the major impacts of invasion experienced by Indigenous Australians, and demonstrate their remarkable survival, resilience and recovery over the past century," said lead author Associate Professor Alan Williams, a Partner Investigator in CIEHF representing EMM Consulting and who is also an Adjunct Research Fellow at James Cook University.
Although the Indigenous population in Australia has grown since the 1950s, the 2021 census shows it remains at about 37 per cent of the estimated median pre-colonial size.
If current growth trends continue, achieving parity with the 1788 Indigenous population would not be reached until around 2047.
"The findings highlight the scale of demographic catastrophe experienced by Indigenous Australians due to colonisation, with the implications being a heightened understanding of intergenerational trauma and to inform future policy that assists Indigenous people. In addition to recognising this intergenerational trauma and disadvantage, it is also time to recognise intergenerational privilege," said co-author, Distinguished Professor Lynette Russell of the Monash University Indigenous Studies Centre and CIEHF.
The researchers also say the study emphasises the importance of using multiple approaches to reconstruct population histories if historical records are incomplete or biased.
"These research findings challenge us to rethink the scale of what happened after 1788. We are not talking about a marginal consequence of colonisation but a demographic catastrophe at the heart of the Australian story. But the research also tells us something extraordinary. Our survival is one of Australian history's most remarkable stories," said Distinguished Professor Larissa Behrendt AO Chair, CIEHF Centre Advisory Committee.
The research - Large size of the Australian Indigenous population prior to its massive decline following colonial invasion, by Alan Williams, Raymond Tobler, Billy Griffiths, Sean Ulm, Matthew Nitschke, Michael Bird, Shane Ingrey, Frédérik Saltré, Kirsty Beller, Ian McNiven, Nicholas Pitt, Lynette Russell, Alistair Paterson, Christopher Wilson and Corey Bradshaw - has been published in Nature Human Behaviour. DOI: 10.1038/s41562-026-02571-9
The research was funded jointly by the Australian Research Council Centre of Excellence for Indigenous and Environmental Histories and Futures (CE230100009), and the Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage (CE17010001).
