Easter Island, home of the enormous statues called moai, is a tiny dot of volcanic matter in the South Pacific Ocean. Called by Chileans the Isla de Pascua, Easter Island is known as Rapanui by its inhabitants, today primarily newcomers from Chile and the Polynesian islands.
Original Settlement of Easter Island
Genetic research has shown that Easter Island was settled by about 40 Polynesians, who landed on the island ~700 AD and went on, undisturbed, for several centuries. During that time, the population grew, reaching a total population of perhaps some 10,000 at its height, ca 1000 AD. The original Easter Islanders were hunters and fishers, relying on the large variety of birds that made the island, covered at the time with a lush palm tree forest, their home.
The most striking feature of the island are the moai, over 900 large stone statues or megaliths of faces, between 6 and 33 feet high. Construction of the moai is thought to have begun ~AD 1000-1100 and ended ~AD 1680. Each was carved out of the Rano Raraku quarry, a volcanic crater on Rapanui. More than 300 unfinished moai are still in place there—the largest unfinished statue at Rano Raruku is over 60 feet tall. Moai were moved by the islanders distances of up to 10 miles to prepared sites all over the island, set upright and decorated with inlaid coral eyes and a 'pukao', a hat of red scoria.
Ecological Disaster at Easter Island
The feverish construction of the moai apparently caused the breakdown of the society. The palm tree forest was cut down for housing and to allow agricultural fields, but primarily, it must be said, to move the enormous moai into place. As the palm trees and shrubs disappeared—18 different plant species went extinct—the birds left, and without palm trees to build canoes, the people were unable to fish. According to dated pollen core samples from an interior lake, the sharpest decline (90%) took place ca 1150-1165 cal AD. After that, the society apparently devolved to warfare, as evidenced by human skeletal remains showing the effects of violence and the presence of stone tool weapons about 1100 AD and increasing over time. The violence was also aimed at the moai, with many of them toppled and broken. The last of the trees were gone ~1475–1500 AD.
The records of the rise and fall of Easter Island's population are found in the archaeological remnants of the society: the pollen, skeletal remains, and other elements show that the survivors of the violence were able to adapt to the crisis and rebuilt a system of agriculture based on sweet potatoes and sugar cane. By the time the Dutch landed in 1722, however, the society had recovered and rebuilt peaceful farming communities with a population of about 3,000.
But the Dutch and British brought syphilis with them, devastating the population. In 1866, Peruvian kidnappers took half the remaining population away and enslaved them. A year later, they brought 15 survivors back to the island, some of whom had contracted smallpox. By 1872, there were no more than 110 descendants of the original inhabitants of Easter Island.
Agriculture on Easter Island
Horticulture was being practiced on the island by AD 1300, evidenced by the remains of house gardens, horticultural fields and chicken houses. Crops were tended or grown in a mixed-crop, dryland production systems, growing yams, sweet potatoes, bottle gourd, sugar cane, taro and bananas. "Lithic mulch" was used to increase soil fertility; rock walls and stone circle planting pits helped protect the crops from wind and rain erosion as the deforestation cycle continued.
Easter Island Archaeology
Ongoing archaeological research about Easter Island concerns the reasons for the environmental degradation and the end of the society about 1500 AD. One study argues that a colonization of the island by the Pacific rat (Rattus exulans) may have exacerbated the end of the palm trees; another says that climatic changes had an effect on the agricultural stability of the economy.
The dating of all events at Easter Island is under debate as well, with some researchers arguing the original colonization took place later, or that the birds and palm trees were gone as early as AD 900. Most argue that the major deforestation took place over a period of about 200 years; which 200 years seem to be the biggest question.
The precise manner in which the moai were transported across the island—dragged horizontally or walked upright—has also been debated. Both methods have been tried experimentally and were successful in erecting moai.
Sources
See the photo essay Moai in their Landscape for more images and information
Bahn, Paul. 1996. Easter Island Decipherment. Archaeology 49(4). Abstract free online.
Barnes, S. S., E. Matisoo-Smith, and T. L. Hunt 2006 Ancient DNA of the Pacific rat (Rattus exulans) from Rapa Nui (Easter Island). Journal of Archaeological Science 33:1536-1540.
Cole, Anthony and John Flenley 2008 Modelling human population change on Easter Island far-from-equilibrium. Quaternary International 184(1):150-165.
Horrocks, Mark and Joan A. Wozniak 2008 Plant microfossil analysis reveals disturbed forest and a mixed-crop, dryland production system at Te Niu, Easter Island. Journal of Archaeological Science 35(1):126-142.
Hunt, Terry L. 2007 Rethinking Easter Island’s ecological catastrophe. Journal of Archaeological Science 34:485-502.
Hunt, Terry L. and Carl P. Lipo 2006 Late Colonization of Easter Island. Science 311(5767):1603—1606.
Louwagie, Geertrui, Christopher M. Stevenson, and Roger Langohr 2006 The impact of moderate to marginal land suitability on prehistoric agricultural production and models of adaptive strategies for Easter Island (Rapa Nui, Chile). Journal of Anthropological Archaeology 25:290–317.
Mann, Daniel, et al. 2008 Drought, vegetation change, and human history on Rapa Nui (Isla de Pascua, Easter Island). Quaternary Research 69(1):16-28.
Prebble, M. and J. L. Dowe 2008 The late Quaternary decline and extinction of palms on oceanic Pacific islands. Quaternary Science Reviews 27(27-28):2546-2567.
Van Tilburg, Jo Anne and Ted Ralston. 1999. Engineers of Easter Island. Archaeology 52(6). Abstract free online.
