A new chronology for the Māori settlement of Aotearoa (NZ) and the potential role of climate change in demographic developments

Understanding the role of climate change, resource availability, and population growth on human mobility remains critically important in anthropology. Researching linkages between climate and demographic changes during the short settlement history of Aotearoa (New Zealand) requires temporal precision equivalent to the period of a single generation. However, current modeling approaches frequently use small terrestrial radiocarbon datasets, a practice that obscures past Māori population patterns and their connection to changing climate. Our systematic analysis of terrestrial and marine 14C ages has enabled robust assessments of the largest dataset yet collated from island contexts. This analysis has been made possible by the recent development of a temporal marine correction for southern Pacific waters, and our findings show the shortcomings of previous models. We demonstrate that human settlement in the mid-late 13th century AD is unambiguous. We highlight early (AD 1250-1275) settlement in the North Island. The South Island was reached a decade later (AD 1280-1295), where the hunting of giant flightless moa commenced (AD 1300-1415), and the population rapidly grew. Population growth levelled off around AD 1340 and declined between AD 1380 and 1420, synchronous with the onset of the Little Ice Age and moa loss as an important food source. The population continued to grow in the more economically stable north, where conditions for horticulture were optimal. The enhanced precision of this research afforded by the robust analysis of marine dates opens up unique opportunities to investigate interconnectivity in Polynesia and inform the patterns seen in other island contexts

Understanding climate resilience in Scandinavia during the Neolithic and Early Bronze Age

Mid and late-Holocene climate shifts are considered to have profoundly shaped demographic developments and adaptive responses of communities globally. Yet their onset, duration, and impact on Neolithic and Early Nordic Bronze Age communities in the high-latitude ranges of southern and north-western Scandinavia remain a major research gap. Here, we built on an emerging body of archaeological and paleoclimate data, encompassing 20,908 anthropogenic 14C dates and 49 climate records from the Holocene. Additionally, we gathered and correlated a new archaeological dataset of 3649 houses from southern Scandinavia and southern Norway. In this study, we utilised 6268 reliable 14C dates and 2519 dwellings to generate time series and socio-economic trends from ∼4100 to 1100 BCE. Our study revealed three key findings: (1) A distinct lateral zonation, with variations in the duration and timing of the Holocene Thermal Maximum (∼7050–2050 BCE). In Southern Scandinavia, a warmer climate may have facilitated the spread of crop cultivation (3820–3790 BCE), coinciding with significant population growth. Neolithic communities settled in permanent two-aisled houses 90–160 years later (3700–3660 BCE). (2) The 2250 BCE (4.2 ka BP) cooling trend marked the beginning of a climate regime shift with varying duration and timing (∼3450–1450 BCE). This period coincided with demographic growth, migration, crop cultivation diversity, and the development of houses with crop storage facilities (2290–2215 BCE). (3) Severe abrupt cooling periods (∼1850–1450 BCE) corresponded to short-term demographic decline including disruptions in trade networks with continental Europe. However, repopulation and redistribution of wealth (∼1450 BCE), along with the development of stable three-aisled houses (1475–1450 BCE), underscore the resilience of food-producing economies in mitigating environmental disturbances

Australian marine radiocarbon reservoir effects: ΔR atlas and ΔR calculator for Australian mainland coasts and near-shore islands

Studies of pre-bomb mollusks live-collected around the Australian coastline have concluded that near-shore marine radiocarbon reservoir effects are small and relatively uniform. These studies are based on limited samples of sometimes dubious quality representing only selective parts of Australia’s lengthy coastline. We systematically examine spatial variability in the marine radiocarbon reservoir effect (ΔR) through analysis of 292 live-collected mollusk samples across the Australian mainland coasts and near-shore islands subject to strict selection criteria. This study presents 233 new ΔR values combined with an evaluation of 59 previously published values. Results demonstrate significant spatial variability in marine radiocarbon reservoir effects across the study region. ΔR values range from 68 ± 24 14C years off the Pilbara region of Western Australia to –337 ± 46 14C years in the southern Gulf of Carpentaria in Queensland. Most sets of local values exhibit internal consistency, reflecting the dominant influence of regional oceanography, including depletion in ΔR values southwards along the eastern Australian coastline coincident with the East Australian Current. Anomalous values are attributed to inaccurate documentation, species-specific relationships with the carbon cycle and/or short-term fluctuations in marine radiocarbon activities. To account for the heterogeneous distribution of marine 14C, we recommend using a location specific ΔR value calculated using the Australian ΔR Calculator, available at: https://delta-r-calc.jcu.io/

New research shows ancestral Māori adapted quickly in the face of rapid climate change

[Extract] When the ancestors of Māori made landfall in Aotearoa some 750 years ago, it marked the final stop of the greatest expansion of human migration in prehistory. Much of their story – exactly when they arrived and where they initially settled, how quickly the population grew, and how they sustained themselves and adapted during rapidly changing climate conditions – has remained elusive until now. Our research traces the first 250 years of settlement, including changes in resource availability and population growth. It provides a more precise timeline for arrival and settlement, beginning as early as 1250-1270

The Aotearoa/New Zealand Radiocarbon Database Upgrade

For the last 20 years, New Zealand researchers have had limited access to a large number of radiocarbon dates measured on archaeological materials. The most used resource containing this type of information, the NZ Radiocarbon Database (McFadgen et al. 2000), has not been updated since 2002, leaving researchers to create their own, often selective datasets for analysis (e.g., Bickler 2018a, 2019; Bickler et al. 2013; Brown 2014, Brown and Crema 2019, Wilmshurst et al. 2011). Consequently, many radiocarbon dates have fallen into obscurity. Here we introduce a new online geospatial database for NZ archaeological radiocarbon data that incorporates and adds to these older datasets. This project has identified over 5100 radiocarbon records associated with archaeological sites and artefacts, of which more than 4100, having met the minimum auditing requirements, are included in a new database release

Global Patterns in Island Colonization during the Holocene

Abstract: Analysis of the spatial and temporal structure of global island colonization allows us to frame the extent of insular human cultural diversity, model the impact of common environmental factors cross-culturally, and understand the contribution of island maritime societies to big historical processes. No such analysis has, however, been undertaken since the 1980s. In this paper we review and update global patterns in island colonization, synthesizing data from all the major island groups and theaters and undertaking quantitative and qualitative analysis of these data. We demonstrate the continued relevance of certain biogeographic and environmental factors in structuring how humans colonized islands during the Holocene. Our analysis also suggests the importance of other factors, some previously anticipated—such as culturally ingrained seafaring traditions and technological enhancement of dispersal capacity—but some not, such as the relationship between demographic growth and connectivity, differing trophic limitations impinging on colonizing farmers versus hunter-gatherer-foragers, and the constraining effects of latitude. We also connect colonization with continental dynamics: both the horizontal transmission of farming lifestyles earlier in the Holocene, and subsequent centrifugal processes associated with early state formation later in the Holocene

Early Aboriginal pottery production and offshore island occupation on Jiigurru (Lizard Island group), Great Barrier Reef, Australia

Aboriginal manufacture and use of pottery was unknown in Australia prior to European settlement, despite well-known ceramic-making traditions in southern Papua New Guinea, eastern Indonesia, and the western Pacific. The absence of ancient pottery manufacture in mainland Australia has long puzzled researchers given other documented deep time Aboriginal exchange networks across the continent and the close proximity of pottery-bearing Lapita and post-Lapita maritime communities in the western Pacific with ocean-going watercraft and sophisticated navigation abilities. We report the oldest securely dated ceramics found in Australia from archaeological excavations on Jiigurru (Lizard Island Group) on the Great Barrier Reef, northeast Australia. Comprehensive radiocarbon dating and Bayesian modelling constrains ceramic deposition to between 2950–2545 cal BP and 1970–1815 cal BP. This timing overlaps with late Lapita and post-Lapita ceramic traditions of southern Papua New Guinea. Geological characterisation of the sherds strongly suggests local manufacture as the vessels belong to three temper and clay groups locally sourced to northeast Australia, and most likely to Jiigurru. The oldest occupation layers date to 6510–5790 cal BP, making Jiigurru the earliest offshore island occupied on the northern Great Barrier Reef. The results demonstrate that northeast Australian First Nations communities had sophisticated canoe voyaging technology and open-sea navigational skills and were intimately engaged in ancient maritime networks, connecting them with peoples, knowledges, and technologies across the Coral Sea region.</p