New study estimates Australia’s pre-colonial Indigenous population at about 2.22 million and a 93% decline by 1861

A national research team led through the Australian Research Council Centre of Excellence for Indigenous and Environmental Histories and Futures produced new population reconstructions that raise the estimated size of Australia's Indigenous population before European colonization. The median figure is 2.22 million people for 1788—up to seven times higher than some earlier estimates that traced back to Alfred Radcliffe-Brown's 1930s work.

Early estimates were calculated long after colonization had begun. The first comprehensive estimates emerged more than a century following the arrival of Britain's First Fleet in 1788. By then, disease, frontier violence, and other forms of harm had already reduced Indigenous communities, so later counts understate the pre-invasion population.

The researchers combined multiple lines of evidence to reconstruct population size and trajectory through time:

• Genetic reconstructions and archaeological evidence to infer past population sizes and distribution.
• Ethnographic observations to provide context and qualitative support for demographic patterns.
• Environmental carrying-capacity models to estimate how many people Australia's varied ecosystems could sustain.

The resulting models produce a median pre-colonial population estimate of 2.22 million and calculate mortality trajectories that align that starting population with early census figures.

• Median estimated population in 1788: 2.22 million.
• Estimated population by 1861: about 7% of the 1788 size, implying roughly a 93% decline over 73 years.
• Excess deaths between 1788 and 1861 (to reconcile the starting estimate with later census counts): about 2.06 million total, or an average of roughly 28,200 excess deaths per year.

The study attributes the demographic collapse to epidemic disease introduced or amplified by contact, direct frontier violence, and structural violence—harm produced by institutions and social systems. The researchers present these figures as a recalibration of historical scale rather than proof of a single causal mechanism, though they emphasize disease and violence as major contributing factors.

Researchers frame the findings as relevant to historical truth-telling and current policy discussions. They argue that recognizing a larger pre-colonial population and the scale of subsequent losses can inform understanding of intergenerational trauma and disadvantage. The research team also notes the long-term demographic recovery since the mid-20th century, with the 2021 census count still at about 37% of the study's median pre-colonial estimate.

Members of the team described the results as a challenge to long-standing assumptions about scale. They emphasize the importance of working with Indigenous partners and using multiple data sources when reconstructing histories where written records are incomplete or biased.

The study revises how historians, policymakers and the public should think about the demographic effects of colonization in Australia. It provides a quantifiable estimate for the scale of population loss in the 19th century and suggests that recovery and survival across subsequent generations occurred after a demographic catastrophe.

Next steps signaled by the research

The paper uses integrated methods that other researchers can apply to refine regional estimates, extend timelines, and investigate local patterns of contact, disease spread and violence. The authors link their findings to discussions about reconciliation, historical recognition and policy measures that address intergenerational consequences.