Discovery of the Tamahere Remains and Their Historical Context
The Tamahere site S14/487 in the Waikato region of New Zealand yielded a remarkable find during routine roadworks for the Waikato Expressway. Archaeologists uncovered the commingled remains of seven Māori tūpuna, or ancestors, dated to approximately 250–170 calibrated years before present, placing them in the Traditional Period of Māori history, around 1700–1780 CE. This era was marked by sophisticated art, architecture, cosmology, and genealogy known as whakapapa. The burial was a secondary one, placed in a borrow pit originally used for extracting soil to enrich kūmara gardens, highlighting the deep integration of horticulture into daily life and mortuary practices.
The site lies within the Waikato Horticultural Complex, an area rich in evidence of intensive root crop cultivation from the 16th century. Mana whenua groups—Ngāti Maahanga, Ngāti Wairere, Ngāti Koroki Kahukura, and Ngāti Hauā—played a pivotal role, approving the research and guiding ethical considerations. Lead archaeologist Sian Keith from Sian Keith Archaeology Ltd emphasized the collaborative nature, stating that tribal knowledge and authority were fundamental.
Advanced Scientific Methods Uncover Dietary Secrets
To reconstruct the diets of these ancestors, researchers employed state-of-the-art techniques including stable isotope analysis of bone collagen for carbon (δ¹³C) and nitrogen (δ¹⁵N), strontium isotopes (⁸⁷Sr/⁸⁶Sr) for residency, dentine micropunch sampling for childhood diet trajectories, and enamel peptide analysis for chromosomal sex determination. Bone collagen quality was rigorously assessed, with all samples meeting preservation criteria (C:N ratios 2.9–3.6).
Isotopes distinguish between C3 plants (like kūmara and taro), C4 plants, marine resources, and terrestrial animals. Peptide analysis via LC-MS/MS on first molars confirmed sexes: one chromosomally female (Kōiwi 2, aged 7–9 years) and one male (Kōiwi 4, 9–15 years). These methods provided unprecedented resolution, revealing not just adult diets but weaning patterns and local origins.
Evidence of Predominantly Plant-Based Diets
The isotope data painted a clear picture: all seven individuals had diets dominated by low-trophic-level C3 terrestrial plants. Corrected whole diet δ¹³C values ranged from -25.5‰ to -25.9‰, consistent with staples like kūmara (sweet potato, Ipomoea batatas), taro (Colocasia esculenta), and uwhikāho (Cordyline spp.). δ¹⁵N values (6.7–9.0‰) indicated minimal animal protein intake, ruling out heavy reliance on marine fish or moa-like birds extinct by this time.
A strong positive correlation between δ¹³C and δ¹⁵N (Spearman’s rs=0.94, p<0.01) suggests trophic consistency, with possible sporadic freshwater (e.g., eels) or terrestrial sources (birds, rats). Tooth wear showed caries and attrition typical of starchy, soft foods, further supporting horticultural crops. Strontium ratios (0.706533–0.706611) confirmed local residency near Tamahere or Rotorua Lakes.
Childhood Weaning and Early Plant Integration
Dentine serial sampling tracked childhood diets. For the two analyzed children, breastfeeding lasted 2.5–3.2 years, with weaning onto C3 plants by age 2–3. δ¹³C dentine values (-21.1 to -20.0‰) and δ¹⁵N (6.0–11.5‰) showed a sharp shift post-weaning to plant staples, mirroring adult patterns. Tooth carbonate δ¹³C (-13.5 to -13.9‰) reinforced C3 dominance. This early transition underscores horticulture's role in sustaining growing populations.
Photo by Julia Fiander on Unsplash
Horticulture's Central Role in Waikato Māori Society
Waikato's fertile allophanic soils supported large-scale kūmara cultivation from the 16th century, evidenced by garden mounds, pits, and storage rua. The borrow pit burial links death rituals to food production, possibly protecting mana under tapu. Oral histories describe kūmara as a 'child' requiring careful tending, aligning with archaeological soil modifications and pollen records. This intensification enabled population growth, fortified pā (villages), and cultural flourishing, contrasting coastal marine-focused diets.
Compared to early sites like Wairau Bar (1250 CE, broad-spectrum foraging), Waikato diets evolved over 500 years toward plant reliance, adapting Polynesian introductions to temperate climates.
Read the full study in Nature CommunicationsBurial Practices and Cultural Insights
The commingled secondary burial, with pipi shells as ritual offerings, suggests postmortem processing (defleshing, exposure) before reburial, predating European Christian influences. No perimortem trauma indicates natural deaths. Placement in a cultivation pit may symbolize life-death cycles or protection from enemies, reflecting whakapapa ties to land and food.
New Zealand Universities Driving the Research
University of Otago led via Dr. Rebecca Kinaston, Director of BioArch South and Otago affiliate, specializing in Pacific bioarchaeology. Her team integrated isotopes and peptides, collaborating with University of Edinburgh's Dr. Jonny Geber on osteology. Waikato iwi provided cultural oversight, while local archaeologists like Sian Keith ensured site integrity. This exemplifies NZ higher education's strength in interdisciplinary, mana-enhancing research, supported by facilities at Otago's Department of Anatomy.
Such studies position Otago and partners as leaders in Māori archaeology, fostering tikanga-guided science.
Implications for Māori Oral Histories and Archaeology
The findings validate Māori narratives of kūmara voyages from Hawaiki and intensive gardening's societal role. They challenge assumptions of meat-heavy diets, showing regional variation: inland Waikato prioritized plants, coastal groups fish. This refines models of pre-European adaptation, population dynamics, and sustainability.
University of Otago press release
Photo by wattana phuangphila on Unsplash
Modern Relevance: Sustainability and Plant-Based Trends
Today's Māori kai (food) emphasizes rongoā (medicinal plants) and sustainable harvesting, echoing ancestors' practices. Amid climate challenges, kūmara's low environmental footprint inspires plant-based initiatives. NZ's rising veganism (5–10% population) draws historical parallels, promoting indigenous crops for health and ecology. Universities like Otago explore these links, informing policy on food security.
- Nutritional benefits: Kūmara high in vitamins A/C, fiber.
- Environmental: Low water/meat needs vs. animal agriculture.
- Cultural revival: Community gardens revive mātauranga food.
Future Directions in Māori Bioarchaeology
Expand sampling for robust statistics, ancient DNA for relatedness, broader Waikato sites. Integrate with paleoenvironmental data (pollen, soils) for holistic models. NZ universities plan genomics, advancing decolonized science honoring tūpuna.