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by Diamond, Jared

  The clearest archaeological evidence for some degree of integration among the competing clan territories is that stone statues and their red cylinders, from quarries in the territories of the Tongariki and Hanga Poukura clans respectively, ended up on platforms in all 11 or 12 territories distributed all over the island. Hence the roads to transport the statues and crowns out of those quarries over the island also had to traverse many territories, and a clan living at a distance from the quarries would have needed permission from several intervening clans to transport statues and cylinders across the latter’s territories. Obsidian, the best basalt, fish, and other localized resources similarly became distributed all over Easter. At first, that seems only natural to us moderns living in large politically unified countries like the U.S.: we take it for granted that resources from one coast are routinely transported long distances to other coasts, traversing many other states or provinces en route. But we forget how complicated it has usually been throughout history for one territory to negotiate access to another territory’s resources. A reason why Easter may thus have become integrated, while large Marquesan islands never did, is Easter’s gentle terrain, contrasting with Marquesan valleys so steep-sided that people in adjacent valleys communicated with (or raided) each other mainly by sea rather than overland.

  We now return to the subject that everyone thinks of first at the mention of Easter Island: its giant stone statues (termed moai), and the stone platforms (termed ahu) on which they stood. About 300 ahu have been identified, of which many were small and lacked moai, but about 113 did bear moai, and 25 of them were especially large and elaborate. Each of the island’s dozen territories had between one and five of those large ahu. Most of the statue-bearing ahu are on the coast, oriented so that the ahu and its statues faced inland over the clan’s territory; the statues do not look out to sea.

  The ahu is a rectangular platform, made not of solid stone but of rubble fill held in place by four stone retaining walls of gray basalt. Some of those walls, especially those of Ahu Vinapu, have beautifully fitted stones reminiscent of Inca architecture and prompting Thor Heyerdahl to seek connections with South America. However, the fitted walls of Easter ahu just have stone facing, not big stone blocks as do Inca walls. Nevertheless, one of Easter’s facing slabs still weighs 10 tons, which sounds impressive to us until we compare it with the blocks of up to 361 tons at the Inca fortress of Sacsahuaman. The ahu are up to 13 feet high, and many are extended by lateral wings to a width of up to 500 feet. Hence an ahu’s total weight—from about 300 tons for a small ahu, up to more than 9,000 tons for Ahu Tongariki—dwarfs that of the statues that it supports. We shall return to the significance of this point when we estimate the total effort involved in building Easter’s ahu and moai.

  An ahu’s rear (seaward) retaining wall is approximately vertical, but the front wall slopes down to a flat rectangular plaza about 160 feet on each side. In back of an ahu are crematoria containing the remains of thousands of bodies. In that practice of cremation, Easter was unique in Polynesia, where bodies were otherwise just buried. Today the ahu are dark gray, but originally they were a much more colorful white, yellow, and red: the facing slabs were encrusted with white coral, the stone of a freshly cut moai was yellow, and the moai’s crown and a horizontal band of stone coursing on the front wall of some ahu were red.

  As for the moai, which represent high-ranking ancestors, Jo Anne Van Tilburg has inventoried a total of 887 carved, of which nearly half still remain in Rano Raraku quarry, while most of those transported out of the quarry were erected on ahu (between 1 and 15 per ahu). All statues on ahu were of Rano Raraku tuff, but a few dozen statues elsewhere (the current count is 53) were carved from other types of volcanic stone occurring on the island (variously known as basalt, red scoria, gray scoria, and trachyte). The “average” erected statue was 13 feet tall and weighed about 10 tons. The tallest ever erected successfully, known as Paro, was 32 feet tall but was slender and weighed “only” about 75 tons, and was thus exceeded in weight by the 87-ton slightly shorter but bulkier statue on Ahu Tongariki that taxed Claudio Cristino in his efforts to reerect it with a crane. While islanders successfully transported a statue a few inches taller than Paro to its intended site on Ahu Hanga Te Tenga, it unfortunately fell over during the attempt to erect it. Rano Raraku quarry contains even bigger unfinished statues, including one 70 feet long and weighing about 270 tons. Knowing what we do about Easter Island technology, it seems impossible that the islanders could ever have transported and erected it, and we have to wonder what megalomania possessed its carvers.

  To extraterrestrial-enthusiast Erich von Däniken and others, Easter Island’s statues and platforms seemed unique and in need of special explanation. Actually, they have many precedents in Polynesia, especially in East Polynesia. Stone platforms called marae, used as shrines and often supporting temples, were widespread; three were formerly present on Pitcairn Island, from which the colonists of Easter might have set out. Easter’s ahu differ from marae mainly in being larger and not supporting a temple. The Marquesas and Australs had large stone statues; the Marquesas, Australs, and Pitcairn had statues carved of red scoria, similar to the material used for some Easter statues, while another type of volcanic stone called a tuff (related to Rano Raraku stone) was also used in the Marquesas; Mangareva and Tonga had other stone structures, including on Tonga a well-known big trilithon (a pair of vertical stone pillars supporting a horizontal crosspiece, each pillar weighing about 40 tons); and there were wooden statues on Tahiti and elsewhere. Thus, Easter Island architecture grew out of an existing Polynesian tradition.

  We would of course love to know exactly when Easter Islanders erected their first statues, and how styles and dimensions changed with time. Unfortunately, because stone cannot be radiocarbon-dated, we are forced to rely on indirect dating methods, such as radiocarbon-dated charcoal found in ahu, a method known as obsidian-hydration dating of cleaved obsidian surfaces, styles of discarded statues (assumed to be early ones), and successive stages of reconstruction deduced for some ahu, including those that have been excavated by archaeologists. It seems clear, however, that later statues tended to be taller (though not necessarily heavier), and that the biggest ahu underwent multiple rebuildings with time to become larger and more elaborate. The ahu-building period seems to have fallen mainly in the years A.D. 1000-1600. These indirectly derived dates have recently gained support from a clever study by J. Warren Beck and his colleagues, who applied radiocarbon dating to the carbon contained in the coral used for files and for the statues’ eyes, and contained in the algae whose white nodules decorated the plaza. That direct dating suggests three phases of construction and reconstruction of Ahu Nau Nau at Anakena, the first phase around A.D. 1100 and the last phase ending around 1600. The earliest ahu were probably platforms without any statues, like Polynesian marae elsewhere. Statues inferred to be early were reused in the walls of later ahu and other structures. They tend to be smaller, rounder, and more human than late ones, and to be made of various types of volcanic stone other than Rano Raraku tuff.

  Eventually, Easter Islanders settled on the volcanic tuff from Rano Raraku, for the simple reason that it was infinitely superior for carving. The tuff has a hard surface but an ashlike consistency inside and is thus easier to carve than very hard basalt. As compared to red scoria, the tuff is less breakable and lends itself better to polishing and to carving of details. With time, insofar as we can infer relative dates, Rano Raraku statues became larger, more rectangular, more stylized, and almost mass-produced, although each statue is slightly different from others. Paro, the tallest statue ever erected, was also one of the latest.

  The increase in statue size with time suggests competition between rival chiefs commissioning the statues to outdo each other. That conclusion also screams from an apparently late feature called a pukao: a cylinder of red scoria, weighing up to 12 tons (the weight of Paro’s pukao), mounted as a separate piece to rest on top of a moai’s flat h
ead (Plate 8). (When you read that, just ask yourself: how did islanders without cranes manipulate a 12-ton block so that it balanced on the head of a statue up to 32 feet tall? That is one of the mysteries that drove Erich von Däniken to invoke extraterrestrials. The mundane answer suggested by recent experiments is that the pukao and statue were probably erected together.) We don’t know for sure what the pukao represented; our best guess is a headdress of red birds’ feathers prized throughout Polynesia and reserved for chiefs, or else a hat of feathers and tapa cloth. For instance, when a Spanish exploring expedition reached the Pacific island of Santa Cruz, what really impressed the local people was not Spanish ships, swords, guns, or mirrors, but their red cloth. All pukao are of red scoria from a single quarry, Puna Pau, where (just as is true of moai at the moai workshop on Rano Raraku) I observed unfinished pukao, plus finished ones awaiting transport.

  We know of not more than a hundred pukao, reserved for statues on the biggest and richest ahu built late in Easter prehistory. I cannot resist the thought that they were produced as a show of one-upsmanship. They seem to proclaim: “All right, so you can erect a statue 30 feet high, but look at me: I can put this 12-ton pukao on top of my statue; you try to top that, you wimp!” The pukao that I saw reminded me of the activities of Hollywood moguls living near my home in Los Angeles, similarly displaying their wealth and power by building ever larger, more elaborate, more ostentatious houses. Tycoon Marvin Davis topped previous moguls with his house of 50,000 square feet, so Aaron Spelling had to top that with a house of 56,000 square feet. All that those moguls’ houses lack to make explicit their message of power is a 12-ton red pukao on the house’s highest tower, raised into position without resort to cranes.

  Given the widespread distribution over Polynesia of platforms and statues, why were Easter Islanders the only ones to go overboard, to make by far the largest investment of societal resources in building them, and to erect the biggest ones? At least four different factors cooperated to produce that outcome. First, Rano Raraku tuff is the best stone in the Pacific for carving: to a sculptor used to struggling with basalt and red scoria, it almost cries out, “Carve me!” Second, other Pacific island societies on islands within a few days’ sail of other islands devoted their energy, resources, and labor to interisland trading, raiding, exploration, colonization, and emigration, but those competing outlets were foreclosed for Easter Islanders by their isolation. While chiefs on other Pacific islands could compete for prestige and status by seeking to outdo each other in those interisland activities, “The boys on Easter Island didn’t have those usual games to play,” as one of my students put it. Third, Easter’s gentle terrain and complementary resources in different territories led as we have seen to some integration of the island, thereby letting clans all over the island obtain Rano Raraku stone and go overboard in carving it. If Easter had remained politically fragmented, like the Marquesas, the Tongariki clan in whose territory Rano Raraku lay could have monopolized its stone, or neighboring clans could have barred transport of statues across their territories—as in fact eventually happened. Finally, as we shall see, building platforms and statues required feeding lots of people, a feat made possible by the food surpluses produced by the elite-controlled upland plantations.

  How did all those Easter Islanders, lacking cranes, succeed in carving, transporting, and erecting those statues? Of course we don’t know for sure, because no European ever saw it being done to write about it. But we can make informed guesses from oral traditions of the islanders themselves (especially about erecting statues), from statues in the quarries at successive stages of completion, and from recent experimental tests of different transport methods.

  In Rano Raraku quarry one can see incomplete statues still in the rock face and surrounded by narrow carving canals only about two feet wide. The hand-held basalt picks with which the carvers worked are still at the quarry. The most incomplete statues are nothing more than a block of stone roughly carved out of the rock with the eventual face upwards, and with the back still attached to the underlying cliff below by a long keel of rock. Next to be carved were the head, nose, and ears, followed by the arms, hands, and loincloth. At that stage the keel connecting the statue’s back to the cliff was chipped through, and transport of the statue out of its niche began. All statues in the process of being transported still lack the eye sockets, which were evidently not carved until the statue had been transported to the ahu and erected there. One of the most remarkable recent discoveries about the statues was made in 1979 by Sonia Haoa and Sergio Rapu Haoa, who found buried near an ahu a separate complete eye of white coral with a pupil of red scoria. Subsequently, fragments of other similar eyes were unearthed. When such eyes are inserted into a statue, they create a penetrating, blinding gaze that is awesome to look at. The fact that so few eyes have been recovered suggests that few actually were made, to remain under guard by priests, and to be placed in the sockets only at times of ceremonies.

  The still-visible transport roads on which statues were moved from quarries follow contour lines to avoid the extra work of carrying statues up and down hills, and are up to nine miles long for the west-coast ahu farthest from Rano Raraku. While the task may strike us as daunting, we know that many other prehistoric peoples transported very heavy stones at Stonehenge, Egypt’s pyramids, Teotihuacán, and centers of the Incas and Olmecs, and something can be deduced of the methods in each case. Modern scholars have experimentally tested their various theories of statue transport on Easter by actually moving statues, beginning with Thor Heyerdahl, whose theory was probably wrong because he damaged the tested statue in the process. Subsequent experimenters have variously tried hauling statues either standing or prone, with or without a wooden sled, and on or not on a prepared track of lubricated or unlubricated rollers or else with fixed crossbars. The method most convincing to me is Jo Anne Van Tilburg’s suggestion that Easter Islanders modified the so-called canoe ladders that were widespread on Pacific islands for transporting heavy wooden logs, which had to be cut in the forest and shaped there into dugout canoes and then transported to the coast. The “ladders” consist of a pair of parallel wooden rails joined by fixed wooden crosspieces (not movable rollers) over which the log is dragged. In the New Guinea region I have seen such ladders more than a mile long, extending from the coast hundreds of feet uphill to a forest clearing at which a huge tree was being felled and then hollowed out to make a canoe hull. We know that some of the biggest canoes that the Hawaiians moved over canoe ladders weighed more than an average-size Easter Island moai, so the proposed method is plausible.

  Jo Anne enlisted modern Easter Islanders to put her theory to a test by building such a canoe ladder, mounting a statue prone on a wooden sled, attaching ropes to the sled, and hauling it over the ladder. She found that 50 to 70 people, working five hours per day and dragging the sled five yards at each pull, could transport an average-sized 12-ton statue nine miles in a week. The key, Jo Anne and the islanders discovered, was for all of those people to synchronize their pulling effort, just as canoe paddlers synchronize their paddling strokes. By extrapolation, transport of even big statues like Paro could have been accomplished by a team of 500 adults, which would have been just within the manpower capabilities of an Easter Island clan of one or two thousand people.

  Easter Islanders told Thor Heyerdahl how their ancestors had erected statues on ahu. They were indignant that archaeologists had never deigned to ask them, and they erected a statue for him without a crane to prove their point. Much more information has emerged in the course of subsequent experiments on transporting and erecting statues by William Mulloy, Jo Anne Van Tilburg, Claudio Cristino, and others. The islanders began by building a gently sloping ramp of stones from the plaza up to the top of the front of the platform, and pulling the prone statue with its base end forwards up the ramp. Once the base had reached the platform, they levered the statue’s head an inch or two upwards with logs, slipped stones under the head to support it in the ne
w position, and continued to lever up the head and thereby to tilt the statue increasingly towards the vertical. That left the ahu’s owners with a long ramp of stones, which may then have been dismantled and recycled to create the ahu’s lateral wings. The pukao was probably erected at the same time as the statue itself, both being mounted together in the same supporting frame.

  The most dangerous part of the operation was the final tilting of the statue from a very steep angle to the vertical position, because of the risk that the statue’s momentum in that final tilt might carry it beyond the vertical and tip it off the rear of the platform. Evidently to reduce that risk, the carvers designed the statue so that it was not strictly perpendicular to its flat base but just short of perpendicular (e.g., at an angle of about 87 degrees to the base, rather than 90 degrees). In that way, when they had raised the statue to a stable position with the base flat on the platform, the body was still leaning slightly forwards and at no risk of tipping over backwards. They could then slowly and carefully lever up the front edge of the base that final few degrees, slipping stones under the front of the base to stabilize it, until the body was vertical. But tragic accidents could still occur at that last stage, as evidently happened in the attempt to erect at Ahu Hanga Te Tenga a statue even taller than Paro, which ended with its tipping over and breaking.