Estimating the size of the pre-colonial Indigenous population in Australia and the aftermath of European invasion
(includes code to compare predictions to anthropological/historical accounts, and a demographic model to estimate the number of excess deaths occurring from pre-colonial period to the late 19th Century)
Williams, AN, R Tobler, B Griffiths, S Ulm, MC Nitschke, MI Bird, S Ingrey, F Saltré, K Beller, IJ McNiven, N Pitt, L Russell, A Paterson, C Wilson, CJA Bradshaw. Large size of the Australian Indigenous population prior to its massive decline following colonial invasion. Nature Human Behaviour In review
Estimating the size of Indigenous populations in Australia prior to European colonial invasion is essential to truth-telling and reconciliation. Robust estimates of the population dynamics of pre-colonial Indigenous Australians are poor due to lethal diseases, frontier and structural violence, and absence of systematic censuses. We review ethnographic observations, archaeological and genetic reconstructions, and modelled carrying capacity to infer Indigenous population size prior to colonial invasion. Congruency of the modelled and genetics-based (not historical or ethnographic accounts) estimates suggests a bootstrapped pre-colonial median of 2.22 million, or 0.29 people km-2. This allows an estimate of the number of excess deaths in the post-colonial era. For a median pre-colonial population of 2.22 million, ~ 28,200 excess deaths year-1 (2.06 million deaths in total) would have had to occur over the late 18th and early 19th Centuries from colonial invasion-related mortality to align with census records. These findings highlight the major impacts of invasion experienced by Indigenous Australians, and demonstrate their remarkable survival, resilience, and recovery over the last century. We warn readers that the content of this study is confronting and possibly distressing.
scripts/indigN.R: main analysis script for carrying-capacity estimation, comparison with Binford densities, boosted regression tree (BRT) and generalised addtive model (GAM) fitting, spatially thinned resampling, and demographic back-casting.scripts/source/: supporting functions for matrix population models, information-theoretic model comparison, and R-squared calculations.data/: core model inputs, including Sahul NPP, life-table data, Binford overlays, and rainfall rasters used to define wet-only subsets.out/: generated tables and figures, including BRT/GAM outputs for all points and wet-only points, Moran correlograms, and distance-labelled spatial resampling summaries.
- NppSahul(0-140ka_rawvalues)_Krapp2021.csv.zip: hindcasted Sahul net primary production from Krapp et al.
- world2013lifetable.csv: age-specific human life-table values from Bradshaw & Brook
- bindensModelOverlay.csv: Binford density estimates overlaid on modelled carrying capacity
HGpopdensR: separate codebase for the alternative population-size approach based on Zhu et al. (2021)
The authors acknowledge the sovereign Traditional Owners and custodians (First Nations) of the unceded lands and seas where we live and work, including Bidiagal in Sydney (A.N.W., N.P.), Dharawal in Kamay/Botany Bay (K.B., S.I.), Dharawal in Woolungah/Wollongong (F.S.), Kulin Nation in Naarm/Melbourne (B.G., I.J.M., L.R.), Yirrganydji and Gimuy Walubara Yidinji in Gimuy/Cairns (S.U., M.I.B.), Ngunnawal and Ngambri in Galambary/Canberra (R.T.), Whadjuk Noongar of Boorloo/Perth (A.P.), Ngarrindjeri of Murrundi/lower Murray River, Kurangk/Coorong, and eastern Fleurieu Peninsula (C.W.), Palawa in Nipaluna/Hobart, lutruwitra/Tasmania (C.W.), Kaurna in Tarndanya/Adelaide (C.J.A.B., M.C.N., F.S.), and Peramangk in Bukatila/Mount Lofty Ranges (C.J.A.B.). The authors also acknowledge and recognise the deep historical and cultural harm our truth-telling exposes, and we commiserate sincerely with all First Nations peoples of Australia.
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). L.R. supported by an Australian Research Council Laureate Fellowship (FL190100161). B.G. supported by an Australian Research Council Discovery Early Career Researcher Award (DE220100203).
