What happened to the people of Rapa Nui?

In 1774 Captain Cook also visited the island, while searching for a new continent in the frigid waters of the southern Pacific. After two months at sea, his crew were exhausted and debilitated by scurvy, and in desperate need of provisions. They headed to Rapa Nui, but were surprised by what they found: a barren island with neither wood nor much fresh water on its roughly 164 sq km. “Nature,” Cook noted, “has been exceedingly sparing of her favours to the spot.”

The crew described a population estimated to be no more than 700, lacking in tools, shelter and clothing, who spent all of their time “providing food to support their precarious existence”. The giant stone statues called moai that dotted the island must surely have been produced at an earlier time when the island flourished, for the current population, Cook’s naturalist remarked, had neither tools nor spare time for such vanity projects.

• Listen | Historian Cat Jarman discusses the mysteries of Rapa Nui

In an expedition 12 years later, the French explorer La Pérouse speculated that the islanders’ ancestors must have foolishly cut down all the trees, with disastrous effects for the island’s environment. Later, others doubted that these seemingly simple inhabitants could have possessed the cultural complexity to create the huge statues.

Within a century of La Pérouse’s visit, the island was catastrophically depopulated, and by the 20th century the apparent mysteries of its decline became one of the world’s best-known parables for human selfishness and self-created environmental disasters. But is the truth behind the disappearance of the Rapanui really what we have been led to believe?

Was Rapa Nui a self-inflicted tragedy?

To many, Rapa Nui is best known for its so-called ecocide (ecological suicide), as popularised by the American author Jared Diamond in his bestseller Collapse. Here, Diamond elaborated on the hypothesis, first made by those 18th-century explorers, that the population of Rapa Nui caused its own demise due to selfish environmental destruction.

The hypothesis is grounded in two points. First, that the lush palm trees that formerly covered the island were deliberately cut down to move the moai. The lack of trees rapidly led to soil erosion and poor crop yields, and a shortage of wood for making canoes to catch fish. As the archaeologists Paul Bahn and John Flenley remarked in chilling tones, this deforestation was seen as deliberate and callous: “The person who felled the last tree could see it was the last tree. But he (or she) still felled it.”

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Second, the ecocide hypothesis assumes that there was a major depopulation from several tens of thousands of inhabitants in the island’s heyday to as few as 700 in the 18th century – Captain Cook’s estimate. The reason for this was said to be internecine warfare and even cannibalism, caused by fierce competition over dwindling resources. As a result, carving of moai intensified in attempts to prove status and to stake claim to land. According to the Norwegian anthropologist Thor Heyerdahl, this all culminated in a major battle in 1680 that killed off the majority of one of the island’s tribes.

But is any of this really true? New research and a closer inspection of the sources reveals a very different story.

To really understand Rapa Nui’s history, we need to go back to its origins. When was the island first settled, and by whom? Thor Heyerdahl argued that the population must have originated in the Americas, because of similarities in art found in both places. He also believed that a more superior race must have been responsible for the island’s advanced achievements.

Yet the overwhelming evidence shows that the island was in fact settled by people from the west, from Polynesia. This can be seen in archaeological evidence, such as pottery styles, as well as in linguistics – the native tongue belongs to the Polynesian language family. And studies of ancient DNA extracted from human remains on Rapa Nui have found no evidence of South American DNA before European contact.

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While it was previously thought that the island was settled as early as AD 700, new radiocarbon dates show the settlement took place around AD 1200. Soon, the island was clearly flourishing. A written language – rongorongo – still undeciphered, also appeared.

We have no certain way of estimating how big the population of the island might originally have been, although a recent study suggests it could have supported up to 15,000 people. This uncertainty makes the question of depopulation – a central point in the ecocide hypothesis – a tricky one to assess. The population estimates made by the early explorers vary widely, from 700 to 3,000, in part because they spent very little time on the island at all.

In reality, there is no definite proof that the population declined before European contact. Heyerdahl’s seismic battle of 1680 cannot be proven, although there are ethnographic reports from the early 20th century that suggest there had been some recent warfare between competing island groups. Obsidian flakes known as mata’a, which are frequently found littering the island’s surface, have been interpreted as weapon fragments, suggesting battles were waged across Rapa Nui.

But now, researchers believe the mata’a were in fact domestic tools or even implements used for ritual tasks. Ancient human remains that have been studied from the island show very little evidence of traumatic injury, and there is no evidence for cannibalism either. Perhaps the Rapanui were more peaceful than previously thought?

Why was Rapa Nui barren?

Visitors to the island today will have no trouble recognising Cook’s description of a barren land, with little more than patches of grassland covering its steep, volcanic slopes. The decimation of the landscape, however, can be traced to events that transpired after Cook’s visit: in 1888 the island was annexed by Chile, and between 1903 and 1953 most of it was rented out for intensive sheep farming, which ravaged the local ecosystem. So why did Cook say it was barren earlier?

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We know from archaeological research and pollen samples that the island was once home to large palms and other trees but at some point, these disappeared. The ecocide explanation was that the trees were cut down to transport the moai, but that could not have been the case. Researchers now agree that the statues were not rolled on logs, but rocked. The moai were actually moved from the stone quarries by tying ropes around their heads, pulling on both sides and letting them “walk” down to their final destinations.

So, if the trees were not cut down to move statues, why did they disappear? It seems the main culprits were actually not human at all: instead, the trees disappeared largely because of the Polynesian rat. The slow-growing Jubea – the large palm tree that once existed on the island – produced palm nuts, and the first human settlers on the island brought rats with them. Research on other islands has shown that rats can have a devastating effect on vegetation, because they often subsist on the seeds of native plants. Archaeologists have found ancient palm nuts with distinctive gnaw marks on their shells on the island. This meant that once the older trees disappeared, the palms could not regenerate.

Another blow to the ecocide theory is new research that shows the lack of trees did not cause famine or a major disaster on the island. Instead, archaeological evidence demonstrates that the native Rapanui were actually able to thrive despite difficult environmental circumstances. The islanders subsisted on a number of different plants including banana, taro and sweet potato, which were grown inside stone enclosures called manavai. In order to make the most of the low nutrition in the soil and lack of consistent rainfall, stone mulch – a layer of stones covering the soil surface – was used to increase crop yields.

Chickens were eaten for food and also served as a source of manure, as did guano (seabird excrement). The abundant rats were considered tasty snacks. Although the waters around the island were surprisingly low in marine species, recent chemical analysis of ancient human remains has shown that fish was still an important part of diets.

All in all, researchers now agree that rather than destroying and mismanaging their environment, the Rapanui were well adapted, and highly capable of resilience and sustainable living in a challenging landscape.

What caused Rapa Nui population to collapse?

With little warfare and no major environmental disasters, what, then, caused Rapa Nui’s population to dwindle dramatically by the 19th century? The real disaster was the impact of visitors from Europe and the Americas, which was profound and devastating. Although many of them were relatively peaceful sailors and whalers, the crews of several ships saw the population as a cheap source of labour; even worse, women were frequently raped. By 1830, there was widespread violence between natives and visitors, and sexually transmitted diseases became endemic.

Then, in 1862, a major slave raid was launched from Peru. In the coming years, South American slavers took away as much as half the island’s population, although an international outcry led to a number of the enslaved people being repatriated. Devastatingly, many of those who were allowed to return had been infected with smallpox. The disease had a severe impact on the remaining population, and by 1877 the Rapanui numbered just 111. When Chile took over, the survivors were confined to the enclosed town of Hanga Roa. It was only in the middle of the 20th century that the island could begin its slow road to recovery.

Today, in a gallery on the ground floor of the British Museum, a large, solitary figure serves as a bittersweet reminder of Rapa Nui’s fate. Hoa Hakananai’a, one of the finest and rarest basalt moai, was given to the museum by Queen Victoria in 1869. She had been gifted it by the admiralty after the HMS Topaze had removed it from Rapa Nui on a visit the year before.

While the statue’s presence in London allows millions of visitors from around the globe to appreciate one of the world’s greatest sculptural traditions, the islanders see him as one of their ancestors. His name means “lost or stolen friend”, and the island has formally requested to have him back. The museum has so far declined the request. The future of Hoa Hakananai’a is uncertain, just like the island on which it once stood.

Cat Jarman is an archaeologist who specialises in Rapa Nui and the Viking age

This content first appeared in the April 2022 issue of BBC History Magazine