Around 1600 CE, Rapa Nui, commonly referred to today as Easter Island, was thriving. In fact, the people of Rapa Nui had formed one of the most complex societies in the world relative to its resource base (Ponting 4). Primitive farming settlements covered the island, with each “clan” containing a cluster of small peasant huts. But how was an isolated island with a rudimentary farming base and limited resources able to develop such an advanced society? In his book, A Green History of the World, British revisionist author Clive Ponting credits the unique level of development on Rapa Nui to a surplus in free time due to quick and simple crop production. The diet of the Rapanui consisted primarily of sweet potatoes and chicken (as sweet potatoes were one of the only crops that could grow in the climate conditions of the island). While this diet was very repetitive and fairly boring, it was not time consuming in the slightest (Ponting 4). With ample time for leisure and other activities, local leaders devoted themselves and their clans to rituals and monument construction. Under the direction of these local clan leaders, the people of Rapa Nui constructed impressive stone ceremonial platforms, known as ahu, and massive stone heads, moai (Ponting 4). These structures characterized the complexity and development of the island’s society.
However, when the first Europeans arrived in 1722, they observed a far different society than the one described above. The people of the island were no longer building stone structures and were instead engaged in intertribal warfare and even cannibalism (Ponting 1). But, while the Europeans were dumbstruck by the backwardness of the Rapanui, they were equally as confused by the evidence they saw of a once socially and technologically advanced society. How could the primitive people they were looking at be responsible for the construction, transportation, and erection of beautiful, massive monuments and structures?
Since 1722, several theories have been put forth to explain the sudden and dramatic collapse of the island’s society. For instance, in the 1950s, the Norwegian archaeologist Thor Heyerdahl, proposed that the island had been originally settled by people from South America and that these settlers brought a long tradition of high quality stonework with them. Heyerdahl believed that new settlers arrived at some point and that the Rapa Nui society had subsequently fallen apart due to intertribal conflict between these two groups. However, very few historians and archaeologists agree with Heyerdahl’s findings (Hunt 2-3).
Instead, the widely accepted theory was that the Rapanui destroyed their society through environmental degradation (Hunt 1). As the population of the island increased, the Rapanui began to cut down trees to create farmland, provide fuel, and build homes and canoes. In addition, the islanders felled massive numbers of trees in order to transport their heavy stone moai from the central quarry to all corners of the island. While timber is a “semi-renewable” resource, the Rapanui did not replant trees, and, in a short period of time, the island had almost entirely been deforested (in-class discussion 9/13/16). Even if the Rapanui had replanted trees, deforestation may have occurred because the rate of cutting down trees would likely have exceeded the rate of new plantings. Without timber, the island’s society fell into pieces. Home building was abandoned and many resorted to living in caves and other primitive shelters. Canoe building was also halted, which left the Rapanui stranded on the island. In addition, the lack of tree cover adversely affected soil conditions, reducing crop yields and making the islanders ever more reliant on chickens for nourishment. But, perhaps the most profound impact of the self-inflicted deforestation may have been the destruction of the Rapanui’s complex social and ceremonial life (Ponting 5-6).
This interpretation of Rapa Nui’s downfall has served, for years, as a cautionary tale about the consequences of unsustainable environmental practices. However, several recent studies have made archaeologists rethink the prevailing theory. First, there is growing evidence that the island was not settled until around 1200 CE, hundreds of years later than previously thought (Krulwich). More importantly, newer studies include evidence that suggest rats, not humans, were responsible for much of Rapa Nui’s downfall. But, how could rats be responsible for the destruction of an entire ecosystem? In a 2006 study, archaeologist Terry L. Hunt detailed how a rat population boom could have contributed heavily to the deforestation of an entire island.
Hunt argues that when rats were introduced to Rapa Nui during the original colonization of the island, they found a very inviting environment. Predators were nonexistent (excluding humans) and food was plentiful. In this type of ideal situation, the rat population could have expanded to approximately 3.1 million (Hunt 6). If the rat population did grow to that extent, then it is certainly reasonable to suggest that rats played a major role in the deforestation of Rapa Nui. In fact, the vast majority of the palm seed shells discovered on the island have shown evidence of having been gnawed on by rats, an action that would have affected the trees’ ability to reproduce. In addition to the evidence that indicates rats contributed heavily to deforestation on Rapa Nui, sedimentary analysis appears to reveal that the forest declined before the extensive use of fire by people (Hunt 7). In other words, the tree population shrunk before humans began cutting down trees for fuel.
In reality, the collapse of the once thriving Rapa Nui society was likely due to a combination of human carelessness and a massive rat population, along with several other unknown factors. Maybe Heyerdahl was partially right. Maybe intertribal conflict disrupted a fairly cohesive and prospering society. Maybe, as new research suggests, the Rapanui struggled against natural environmental barriers to success, such as regional climate differences. In 2015, a group of scientists led by Thegn Ladefoged analyzed more than 400 obsidian tools and chipped-off obsidian flakes from six sites across Rapa Nui (Pappas). Because obsidian absorbs water when exposed to air at a predictable rate over time, the researchers were able to determine when the tools were made. Once a timeline was determined, the researchers were able to gauge patterns of human use at the different sites. They focused on three sites in particular and each site showed differences in the rate and time period of decline in obsidian use. Ladefoged and his team then hypothesized that “differences in rainfall levels and soil quality at those sites appear to explain the uneven decline” (Pappas). For example, Site 1, the site where tool use declined first and most rapidly, is dry and infertile. Site 2, where tool use also declined fast, is wetter but still relatively infertile. By contrast, Site 3, the longest-lasting spot in terms of tool use, is both rainy and fertile (Pappas). This new evidence suggests that the Rapanui people were slowly forced to migrate to more fertile parts of the island for survival and that deforestation may have not have played as significant a role in the island’s demise as previously thought.
We will probably never know the complete answer, and no matter the truth, there are still lessons to be learned from the Rapa Nui downfall. On the one hand, if human-led deforestation led to the societal collapse then, as geographer John Flenley and archeologist Paul Bahn write in The Enigmas of Easter Island, the story of Rapa Nui “is a story with an urgent and sobering message for our own times” (Tyson). We, the human race, often do not practice sustainable techniques and this lack of care for the environment could eventually lead to our demise. However, even if humans were not directly responsible for the Rapa Nui failure (i.e. rat-led deforestation), we can still learn from the events that took place on the island. For instance, we can discover that a small, unintentional, human-caused occurrence (such as providing a suitable environment for rats to flourish) can serve as a ratchet and lead to massive environmental changes. And, in the off chance that humans played no role in the island’s demise, we can learn that, in a place with limited geography and a limited resource base, inhabitable locations may eventually run out and the environment may be stressed to a point where societal collapse is inevitable. As new theories continue to appear, each with strong evidence in support, it looks ever more likely that the mystery of Rapa Nui will forever remain unsolved. And whether or not humans caused the downfall of the island, we must be conscious of our actions as we look to provide a future for generations to come.
Hunt, Terry. “Rethinking the Fall of Easter Island.” American Scientist 94.5 (2006): 412. Web.
Krulwich, Robert. “What Happened On Easter Island - A New (Even Scarier) Scenario.” NPR. NPR, 10 Dec. 2013. Web. 19 Sept. 2016.
Pappas, Stephanie. “Easter Island’s Demise May Have Surprising New Explanation.” LiveScience. TechMedia Network, 8 Jan. 2015. Web. 19 Sept. 2016.
Ponting, Clive. A Green History of the World: The Environment and the Collapse of Great Civilizations. New York: St. Martin’s, 1992. Print.
Tyson, Peter. “The Fate of Easter Island.” PBS. PBS, 20 Apr. 2004. Web. 19 Sept. 2016.