Easter Island, or Rapa Nui, never experienced a catastrophic population collapse, according to a new study examining archaeological rock gardens. This finding challenges long-held beliefs that the Rapanui people caused their own downfall through overexploitation of resources. Instead, the study suggests the population was sustainable, never exceeding 3,900 people. However, some experts have critiqued the study’s data.
Located over 2,300 miles from the nearest mainland, Rapa Nui is known for its remote location and famous moai statues. The island was first settled around 1000 A.D., likely by Polynesians. Traditional narratives suggested that deforestation and resource overuse led to the collapse of the Rapanui culture before European contact.
Despite its poor soil and limited freshwater, the Rapanui managed to survive in challenging conditions using techniques like “lithic mulching,” where rocks were added to soil to improve crop yields. Previous estimates suggested the island could support up to 16,000 people at its peak in the 15th century, but the new study revises this figure to a maximum of 3,900.
The study, published in Science Advances on June 21, used shortwave infrared satellite imagery (SWIR) and machine learning to identify rock gardens on the island. These methods showed that rock gardening was less common than previously thought, leading researchers to conclude that the island’s resources could not have supported more than 4,000 people.
Carl Lipo, an archaeologist at Binghamton University and one of the study’s authors, emphasized the Rapanui’s resilience in a harsh environment. “They had to figure out how to survive every single day,” he said, highlighting the importance of community organization and cooperation.
However, some experts remain skeptical. Jo Anne Van Tilburg of UCLA’s Easter Island Statue Project argues that the study oversimplifies the issue by focusing solely on rock gardening. She suggests that other factors influencing soil fertility and subsistence patterns were not adequately considered.
Van Tilburg also questions the conclusion that the population was sustainable, suggesting the low number of rock gardens could indicate “unsuccessful adaptations” for a growing population. Despite these critiques, the study’s population estimate aligns with the size encountered by Europeans in 1722, suggesting a sustainable population of around 3,000 people based on the subsistence strategies used.
This research invites further investigation into the history and sustainability of the Rapanui population, challenging existing assumptions and offering new insights into their survival strategies.
