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Rethinking the Fall of Easter Island

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Recent evidences show that early accounts on Easter Island, or known locally as Rapa Nui, needed revision especially among the dates. Corrections in radiocarbon dating suggests that the first settlers arrived from other Polynesia islands around 1200 A.D. The population increased by 3.4% per year and meant that a colonizing population would have grown to more than a thousand in a about a century suggesting that human population in Rapa Nui had reached a maximum of 3,000 at around 1350 A.D. It appears that the islanders began building moai and ahu soon after reaching the island and by the time Dutch explorer Jacob Roggeveen arrived in 1722, most of the island's trees were gone, but deforestation did not trigger societal collapse, as opposed to the old view. Newly introduced diseases, conflict with Eurpoean invaders and enslavement followed over the next century and a half, and were the chief causes of the collapse. In the early 1860s, more than a thousand Rapanui were taken from the island as slaves, and by the late 1870s the number of native islanders numbered only around 100. In 1888, the island was annexed by Chile.
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Every year, thousands of tourists
from around the world take a long
flight across the South Pacific to see the
famous stone statues of Easter Island.
Since 1722, when the first Europeans ar-
rived, these megalithic figures, or moai,
have intrigued visitors. Interest in how
these artifacts were built and moved led
to another puzzling question: What hap-
pened to the people who created them?
In the prevailing account of the island’s
past, the native inhabitants—who refer to
themselves as the Rapanui and to the is-
land as Rapa Nui—once had a large and
thriving society, but they doomed them-
selves by degrading their environment.
According to this version of events, a
small group of Polynesian settlers arrived
around 800 to 900 a.d., and the island’s
population grew slowly at first. Around
1200 a.d., their growing numbers and an
obsession with building moai led to in-
creased pressure on the environment. By
the end of the 17th century, the Rapanui
had deforested the island, triggering war,
famine and cultural collapse.
Jared Diamond, a geographer and
physiologist at the University of Califor-
nia, Los Angeles, has used Rapa Nui as a
parable of the dangers of environmental
destruction. “In just a few centuries,” he
wrote in a 1995 article for Discover maga-
zine, “the people of Easter Island wiped
out their forest, drove their plants and ani-
mals to extinction, and saw their complex
society spiral into chaos and cannibalism.
Are we about to follow their lead?” In his
2005 book Collapse, Diamond described
Rapa Nui as “the clearest example of a
society that destroyed itself by overex-
ploiting its own resources.”
Two key elements of Diamond’s
account are the large number of Poly-
nesians living on the island and their
propensity for felling trees. He reviews
estimates of the island’s native popula-
tion and says that he would not be sur-
prised if it exceeded 15,000 at its peak.
Once the large stands of palm trees were
all cut down, the result was “starvation,
a population crash, and a descent into
cannibalism.” When Europeans arrived
in the 18th century, they found only a
small remnant of this civilization.
Diamond is certainly not alone in
seeing Rapa Nui as an environmental
morality tale. In their book Easter Is-
land, Earth Island, authors John R. Flen-
ley of Massey University in New Zea-
land and Paul G. Bahn worried about
what the fate of Rapa Nui means for
the rest of human civilization: “Hu-
mankind’s covetousness is boundless.
Its selfishness appears to be genetically
inborn…. But in a limited ecosystem,
selfishness leads to increasing popula-
tion imbalance, population crash, and
ultimately extinction.”
When I first went to Rapa Nui to con-
duct archaeological research, I expect-
ed to help confirm this story. Instead, I
found evidence that just didn’t fit the
underlying timeline. As I looked more
closely at data from earlier archaeo-
logical excavations and at some similar
work on other Pacific islands, I realized
that much of what was claimed about
Rapa Nui’s prehistory was speculation.
I am now convinced that self-induced
environmental collapse simply does not
explain the fall of the Rapanui.
Rethinking the Fall
of Easter Island
New evidence points to an alternative
explanation for a civilization’s collapse
Terry L. Hunt
Figure 1. British artist William Hodges trav-
eled to Easter Island (or Rapa Nui, as the
island’s inhabitants refer to it) in the 1770s,
inspiring this painting of several of the stone
Terry L. Hunt is a professor in the Department of
Anthropology at the University of Hawaii at Manoa,
where he has taught since 1988. He earned his
master’s degree in anthropology from the University
of Auckland in New Zealand and his Ph.D. in an-
thropology from the University of Washington. Hunt
has been conducting archaeological field research in
the Pacific Islands for nearly 30 years, and he is cur-
rently director of the University of Hawaii Rapa Nui
Archaeological Field School. Address: Department of
Anthropology, University of Hawaii at Manoa, 2424
Maile Way, Saunders Hall, Honolulu, HI 96822.
Internet: thunt@hawaii.edu
2006 September–October 413
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Radiocarbon dates from work I con-
ducted with a colleague and a number
of students over the past several years
and related paleoenvironmental data
point to a different explanation for what
happened on this small isle. The story is
more complex than usually depicted.
The first colonists may not have ar-
rived until centuries later than has been
thought, and they did not travel alone.
They brought along chickens and rats,
both of which served as sources of
food. More important, however, was
what the rats ate. These prolific rodents
may have been the primary cause of
the island’s environmental degrada-
tion. Using Rapa Nui as an example
of “ecocide,” as Diamond has called it,
makes for a compelling narrative, but
the reality of the island’s tragic history
is no less meaningful.
Early Investigations
More than 3,000 kilometers of ocean
separate Rapa Nui from South America,
the nearest continent. The closest hab-
itable island is Pitcairn (settled by the
infamous Bounty mutineers in the 18th
century), which lies more than 2,000 ki-
lometers to the west. Rapa Nui is small,
only about 171 square kilometers, and it
lies just south of the tropics, so its climate
is somewhat less inviting than many
tropical Pacific islands. Strong winds
bearing salt spray and wide fluctuations
in rainfall can make agriculture difficult.
The flora and fauna of Rapa Nui are
limited. Other than chickens and rats,
there are few land vertebrates. Many
of the species of birds that once inhab-
ited the island are now locally extinct.
Large palm trees from the genus Jubaea
long covered much of the island, but
they, too, eventually disappeared. A re-
cent survey of the island found only 48
statues that have made this locale famous. The island continues to draw both tourists and scientists, in part because of the mystery surrounding
the fate of its civilization. A popular account of Rapa Nui’s history casts the inhabitants as the perpetrators and victims of an ecological catas-
trophe that resulted from overexploiting the island’s resources. New evidence from archaeological work and comparative ecology, however,
reveals that this story may need to be rewritten.
National Maritime Museum, London
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different kinds of native plants, includ-
ing 14 introduced by the Rapanui.
Accounts by European visitors to
Rapa Nui have been used to argue
that by the time of European discov-
ery in 1722 the Rapanui were in a state
of decline, but the reports are some-
times contradictory. In his log, Dutch
explorer Jacob Roggeveen, who led the
first Europeans to set foot on Rapa Nui,
portrayed the island as impoverished
and treeless. After they left, however,
Roggeveen and the commanders of his
three ships described it as “exceedingly
fruitful, producing bananas, potatoes,
sugar-cane of remarkable thickness, and
many other kinds of the fruits of the
earth…. This land, as far as its rich soil
and good climate are concerned is such
that it might be made into an earthly
Paradise, if it were properly worked
and cultivated.” In his own account of
the voyage, one of Roggeveen’s com-
manders later wrote that he had spot-
ted “whole tracts of woodland” in the
distance.
A 19th-century European visitor, J. L.
Palmer, stated in the Journal of the Roy-
al Geographic Society that he had seen
“boles of large trees, Edwardsia, coco
palm, and hibiscus.” Coconut trees are
a recent introduction to the island, so
Palmer might have seen the now-extinct
Jubaea palm.
Clearly the historical record leaves
many gaps to be filled. Scientists have
long tried to provide more definitive
answers about Easter Island’s prehis-
tory, but at times have instead contrib-
uted to the confusion.
Norwegian explorer and anthropolo-
gist Thor Heyerdahl, for example, vis-
ited Rapa Nui in the 1950s and sparked
widespread interest in the moai and
the large stone foundations, or ahu, on
which they were often placed. But he
also helped to spread some misleading
conclusions. Heyerdahl believed that the
Polynesian islands, including Rapa Nui,
were settled by voyagers from South
America rather than from the western
Pacific. In 1947, he launched his famous
Kon-Tiki expedition, directing a small
craft made of wood and other basic ma-
terials from Peru to the Tuamotu Islands
to prove that the journey would have
been possible for prehistoric peoples.
In 1955, Heyerdahl led an archaeolog-
ical expedition on Rapa Nui. He argued
that the island had been settled from
the east, and he pointed to similarities
between the island’s statues and South
American stonework. Linguistic and ge-
netic evidence have firmly established
the Polynesian origin of the Rapanui,
but Heyerdahl’s conclusions still cloud
the archaeological record.
A charcoal sample uncovered on
Poike Peninsula—marking, presumably,
the site of an ancient hearth—was dated
to about 400 a.d. Combined with the
then-prevailing idea that the Rapanui
language showed many centuries of iso-
lation from other Polynesian groups, the
radiocarbon date from this charcoal sam-
ple led scholars to conclude that human
settlement here began about 400 a.d.
More recently, however, archaeolo-
gists have rejected the Poike Peninsula
date. Likewise, others have questioned
whether the linguistic evidence reflects
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Figure 3. Although it is a small island, Rapa Nui has an abundance of archaeological riches.
The author led excavations on Anakena Beach, thought to be the location of the earliest human
settlements. Other important archaeological sites include three crater-tipped peaks—Rano
Kau, Rano Aroi and Rano Raraku—and the Poike Peninsula. Black dots indicate the positions
of numerous ahu, foundation stones supporting the island’s impressive carved-rock statues.
Figure 2. Often referred to as the most isolated habitable island in the world, Rapa Nui lies
more than 2,000 kilometers from Pitcairn Island and more than 3,000 kilometers from Chile,
which annexed the island in 1888.
2006 September–October 415
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Rapanui’s isolation instead of early
settlement. This later phase of research
began to point to 800–900 a.d. as the ear-
liest likely date of human colonization.
Although archaeologists have indeed
focused a great deal of effort on estab-
lishing just when the island was settled,
much of their work has been dedicated
to studying the changes that these col-
onists brought about, especially defor-
estation. Heyerdahl’s team took pollen
samples that showed that palm trees had
once been abundant on the island. In the
course of their excavations, members of
the expedition also found telltale features
where roots had once grown, indicating
more widespread vegetation in the past
and pointing to the possibility that hu-
mans had caused the loss of forest cover.
Flenley has provided much of the
more recent detailed evidence in this
area. In the late 1970s and 1980s, he
collected and analyzed sediment core
deposits from three areas: Rano Aroi,
a crater near the island’s center; Rano
Raraku, a crater adjacent to the quarry
where many of the statues were carved;
and Rano Kau, a crater in the southwest
corner of the island. Each of these de-
pressions hosts a shallow lake, which
collects wind-blown sediment from
elsewhere on the island.
The best evidence came from a 10.5-
meter core from Rano Kau, which
showed that the island had been for-
ested for tens of thousands of years
before the trees disappeared, a process
that took place between 800 and 1500
a.d. But more recently Flenley and other
scientists have raised doubts about the
validity of these dates, which were de-
rived from measurements of the radio-
carbon age of lake sediment samples. In
2004, Kevin Butler of Massey University,
Christine A. Prior of Rafter Radiocar-
bon Laboratory and Flenley showed
that bulk sediment samples from such
locales often contain some carbon that
is considerably older than the time of
deposition, suggesting that the chronol-
ogy Flenley first proposed may be hun-
dreds of years too old in dating human-
induced forest clearance.
Other recent archaeological and paleo-
environmental work has also chal-
lenged long-held assumptions about
Rapa Nui’s prehistory. Catherine Orliac
of the Centre national de la recherche
scientifique in France has conducted a
remarkable study of 32,960 specimens of
woods, seeds, fibers and roots. In addi-
tion to identifying 14 taxa not previously
observed on the island, she showed that
the primary source of fuel for the Ra-
panui changed in a dramatic fashion.
Between 1300 and 1650 a.d., inhabitants
burned wood from trees, but they used
grass, ferns and other similar plants for
fuel after that point. Orliac also argued,
however, that at least 10 taxa of forest
vegetation may have persisted until Eu-
ropeans began visiting the island.
In another study, Orliac examined the
remains of the hard shells surround-
ing the seeds of the Jubaea palm. Those
samples that were carbonized, gnawed
by rats or found in association with hu-
man materials provided evidence of hu-
man habitation on the island. She dated
a number of such remains and found
that they all fell after 1250 a.d.
Ecologists Andreas Mieth and Hans-
Rudolf Bork of Christian-Albrechts-
University Kiel in Germany have studied
the process of deforestation on Rapa Nui.
Using a variety of evidence, primarily
from Poike Peninsula, they concluded
that Jubaea palms once covered most of
the island. Around 1280 a.d., they argued,
deforestation began. The Rapanui large-
ly abandoned the peninsula within 200
years, but then they resettled it in some
areas from about 1500 a.d. to 1675 a.d.
In 2003, geologist Dan Mann and sev-
eral colleagues obtained radiocarbon
dates not from bulk samples, but from
bits of charcoal found in soils from a
number of locations around the island.
They also documented ancient episodes
of severe erosion, which according to
their radiocarbon measurement began
soon after 1200 a.d. Their study, like that
of Mieth and Bork, pointed to defores-
tation taking place between 1200 and
1650 a.d., with no sign of human impact
prior to that period.
Both Mann’s team and Mieth and
Bork reconciled their findings with ear-
lier work by arguing that the popula-
tion during the centuries prior to 1200
a.d. must have been small or transient. It
was only once the number of permanent
inhabitants grew larger that indications
of human presence would have become
clear in the paleoenvironmental record.
But this scenario makes several ques-
tionable assumptions. It requires a small
founding population with a slow rate
of growth and little ecological impact.
After conducting our own research on
Rapa Nui, we began to wonder whether
the lack of evidence of human presence
prior to about 1200 a.d. should be taken
at face value—maybe the island hadn’t
actually been settled as early as most
people assumed.
Timing Is Everything
I did not expect when I first visited Rapa
Nui, in May 2000, that I would end up
questioning what I thought I knew about
the island’s past. Indeed, my initial trip
to the island was primarily as a tourist,
not as an archaeologist. But while I was
there, I ran into Sergio Rapu, the first
native Rapanui governor of the island
and a former student of mine—Rapu
had studied archaeology as a graduate
student at the University of Hawaii. He
invited me to do research on Rapa Nui.
Before that point, the thought of do-
ing work there had not really crossed
my mind. I had been planning to lead a
continuing archaeological field school in
Fiji later that summer, but when a vio-
lent coup d’état began there that May,
my enthusiasm waned. Rapa Nui now
seemed an increasingly appealing place
to hold the field school sessions.
I anticipated that the work of my stu-
dents and I, which we began in August
Figure 4. Thor Heyerdahl, an anthropologist
and explorer, was as famous for his adventur-
ous spirit as for his scientific career. In 1955,
he traveled to Rapa Nui to conduct archaeo-
logical work. His time there brought greater
attention to this far-flung destination but also
contributed to the popularity of a number of
incorrect conclusions about the island’s his-
tory. Here, Heyerdahl is pictured on the Kon-
Tiki, a small balsa-wood boat that Heyerdahl
and several crew members sailed from South
America to a Polynesian island in 1947.
Hulton Archive/Getty Images
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2000, would help put the finishing
touches on a well-established story. But
as I began to review archaeological sur-
vey data, studies of the moai and evi-
dence for environmental changes, I real-
ized that there were a number of gaps in
what was known about Rapa Nui, and
I grew increasingly skeptical of every-
thing said about the island’s prehistory.
Over the next few years, my students
and I conducted field work for one or
two months each year. My colleague
Carl P. Lipo, an archaeologist at Califor-
nia State University, Long Beach, joined
the effort and introduced me to the po-
tential of satellite imagery, which we
used to explore features such as the an-
cient roads on which the Rapanui trans-
ported the moai from the quarry at Rano
Raraku to every corner of the island. Fol-
lowing road alignments also led to the
documentation of a number of moai that
were previously unrecorded.
In 2004, we began new excavations
at a locale called Anakena. This white
sand beach would have been the most
inviting spot for the first colonists to
land their boats (the shore in other
places is for the most part made up of
cliffs or rocky crags). Hence most an-
thropologists suspect the areas around
Anakena to be the site of the earliest
settlements. We intended to study sub-
sistence and environmental change, not
basic chronology, which we assumed
was already settled.
We dug through sand whose beauti-
fully undisturbed stratification proved to
be an archaeologist’s dream. The integrity
of the layers would be helpful in deter-
mining when things happened, both in
an absolute sense and relative to other
events. But the excavations were not easy.
The sand at Anakena is soft and uncon-
solidated. As we dug down a few meters,
the pits became increasingly dangerous.
Horses trotting by on the beach would
cause nerve-wracking vibrations in the
layers of sand; we worried someone
would be buried alive in the pit.
Finally, we reached the bottom of the
sand. In the top 3 to 5 centimeters of the
underlying clay we unearthed abun-
dant charcoal fragments (indicating
the use of fire), bones (including those
of the Polynesian rat, a species that ar-
rived with the colonists) and flaked
obsidian shards (a clear sign of human
handiwork). Below, we found nothing
suggesting human activity. Instead, the
ancient clay was riddled with irregular
voids—places where the soil had once
molded itself around the roots of the
long-gone Jubaea palm tree.
We had clearly found the layer with
the earliest human-related materials at
Anakena, and assuming that Anake-
na was likely the location of the first
settlements on the island, we were in
an excellent position to ascertain the
timing of the initial colonization. So
I was disappointed when I received
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Figure 5. In 2004 and 2005, the author led ex-
cavations on Anakena Beach and found evi-
dence that humans arrived on the island only
about 900 “radiocarbon years” ago, which
after applying the relevant corrections corre-
sponds to around 1200 A.D. Eight dates (with
error bars) from charcoal samples found dur-
ing the digs are mapped onto the stratigraph-
ic layer in which they were found (layers are
not drawn to scale).
Figure 6. Prior studies of samples containing indications of human presence on the island (bits of charcoal, for example, suggesting human-set
fires blazed nearby) yielded 45 published radiocarbon dates older than 750 years (left). Yet after the author and colleague Carl Lipo culled these
data using accepted reliability criteria, only nine dates remained (shaded portions of bars). The majority of the accepted results had radiocarbon
ages close to 900 years (approximately 1200 A.D.). The single sample giving an earlier radiocarbon age showed large measurement uncertainties,
corresponding to a broad range of possible dates between 657 A.D. and 1180 A.D., so it, too, is compatible with the notion that people arrived on
the island around 1200 A.D. Studies of deforestation on Rapa Nui have found signs of human activity beginning about 800 years ago (right).
One explanation for the lack of evidence of human activity before this point is that the initial population was small and had little environmen-
tal impact. But it may be that humans simply did not arrive until about 800 years ago.
2006 September–October 417
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an e-mail from the lab that did the ra-
diocarbon dating on these samples.
There seemed to be a mistake. The old-
est dates were only about 800 years
old, implying that occupation began
around 1200 a.d. The dates from lay-
ers closer to the surface were progres-
sively younger, which is inconsistent
with the possibility that somehow
our samples were contaminated with
modern carbon. There was really no
way to explain these numbers, at least
not within the conventional model of
Rapa Nui’s development. I put aside
the discouraging message for the mo-
ment and decided to try to figure out
later what had gone wrong.
When the hardcopy of the report ar-
rived a couple of weeks later, I exam-
ined the data again. The closer I looked,
the more it seemed that our results were
not the problem. I spoke with my friend
and colleague Atholl Anderson of the
Australian National University. He had
done a careful screening of radiocarbon
dates from New Zealand and conclud-
ed that the first settlers arrived there
around 1200 a.d., several hundred years
later than archaeologists had previous-
ly believed. The reaction to his ideas
was initially quite cool, but time and
additional evidence have proved him
correct. Having had this experience,
Anderson advised me to keep an open
mind and to trust my data more than
any preconceptions.
In 2005, Lipo and I returned with our
students to Anakena and located anoth-
er part of the dune where the deepest
layers containing vestiges of occupation
would be easier to expose. We uncov-
ered a large area of the clay beneath the
sand and took samples for more radio-
carbon dating. The two additional dates
from the basal layer were completely
consistent with our earlier results.
Was the conventional chronology just
plain wrong? Lipo and I took a closer
look at the evidence for earlier human
settlement. We evaluated 45 previously
published radiocarbon dates indicating
human presence more than 750 years
ago using a “chronometric hygiene”
protocol. We rejected dates measured
from unreliable sources, such as marine
organisms, which require corrections for
the older carbon from the marine envi-
ronment. We also rejected single dates
that were not confirmed by a second
date from the same archaeological con-
text. Using only paired dates helps en-
sure the reliability of the data. Our stan-
dards were more inclusive than those
used by Anderson in his study of New
Zealand, but we still were left with only
nine acceptable dates. With this culling,
the evidence for first occupation around
800 a.d. simply fell apart.
Although our results did not fit with
the accepted settlement date for Rapa
Nui, they did match the chronology for
deforestation that Orliac, Mann, and
Mieth and Bork had worked out. You
merely have to abandon the idea that a
small or transient population endured
for centuries. Instead, we posit that from
the start the environmental impact was
widespread.
The notion that humans did not ar-
rive on Rapa Nui until about 1200 a.d.
was not the only thing causing me to re-
think my assumptions about the island.
Research on other Pacific islands pro-
vides a compelling parallel and a pos-
sible explanation for the damage done
to Rapa Nui’s environment.
Rats in Paradise
For thousands of years, most of Rapa
Nui was covered with palm trees. Pol-
len records show that the Jubaea palm
became established at least 35,000
years ago and survived a number of
climatic and environmental changes.
But by the time Roggeveen arrived in
1722, most of these large stands of for-
est had disappeared.
It is not a new observation that virtu-
ally all of the shells housing palm seeds
found in caves or archaeological ex-
cavations of Rapa Nui show evidence
of having been gnawed on by rats, but
Figure 7. For thousands of years, large stands of palm trees covered much of the island. The
closely related Jubaea chilensis (upper left) still survives in Chile and elsewhere, but the trees
disappeared from Rapa Nui in the centuries after people arrived. The landscape remains
largely denuded today, as seen in this view of the area around Ahu Tongariki (upper right).
Although people were probably responsible for some portion of the deforestation, the prin-
cipal cause was a swelling population of Polynesian rats (lower right), which eat palm nuts
and in so doing make it difficult for these trees to regenerate. (Photograph of Ahu Tongariki
courtesy of the author.)
Brian Enting/Photo Researchers, Inc.
Humberto Olea
418 American Scientist, Volume 94 © 2006 Sigma Xi, The Scientific Research Society. Reproduction
with permission only. Contact perms@amsci.org.
the impact of rats on the island’s fate
may have been underestimated. Evi-
dence from elsewhere in the Pacific
shows that rats have often contributed
to deforestation, and they may have
played a major role in Rapa Nui’s envi-
ronmental degradation as well.
Archaeologist J. Stephen Athens of
the International Archaeological Re-
search Institute conducted excavations
on the Hawaiian Island of Oahu and
found that deforestation of the Ewa
Plain took place largely between 900
and 1100 a.d. but that the first evidence
of human presence on this part of the
island was not until about 1250 a.d.
There were no climatic explanations
for the disappearance of palm trees,
but there was evidence that the Poly-
nesian rat (Rattus exulans), introduced
by the first human colonists, was pres-
ent in the area by about 900 a.d. Ath-
ens showed that it was likely rats that
deforested large areas of Oahu.
Paleobotanists have demonstrated
the destructive effect of rats on native
vegetation on a number of other islands
as well, even those as ecologically di-
verse as New Zealand. In areas where
rats are removed, vegetation often re-
covers quickly. And on Nihoa Island, in
the northwest Hawaiian Islands, where
there is no evidence that rats ever be-
came established, the island’s native
vegetation still survives despite prehis-
toric human settlement.
Whether rats were stowaways or a
source of protein for the Polynesian
voyagers, they would have found a wel-
coming environment on Rapa Nui—an
almost unlimited supply of high-quality
food and, other than people, no preda-
tors. In such an ideal setting, rats can
reproduce so quickly that their popula-
tion doubles about every six or seven
weeks. A single mating pair could thus
reach a population of almost 17 million
in just over three years. On Kure Atoll
in the Hawaiian Islands, at a latitude
similar to Rapa Nui but with a smaller
supply of food, the population density
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Figure 8. New evidence casts doubt on the traditional history of Rapa Nui. The popular narrative of environmental collapse hinges on early coloni-
zation and a large peak population (top). A revised timeline that takes into account recent radiocarbon dates points to initial settlement around 1200
A.D. (bottom). According to this version of events, the human population never grew much larger than about 3,000, and rats played a dominant role
in the deforestation of the island. In this scenario, the Rapanui culture did not decline significantly until after the arrival of Europeans. Within about
a century and half of initial contact, however, disease and enslavement reduced the Rapanui population to approximately 100.
2006 September–October 419
www.americanscientist.org © 2006 Sigma Xi, The Scientific Research Society. Reproduction
with permission only. Contact perms@amsci.org.
of the Polynesian rat was reported in
the 1970s to have reached 45 per acre.
On Rapa Nui, that would equate to a
rat population of more than 1.9 mil-
lion. At a density of 75 per acre, which
would not be unreasonable given the
past abundance of food, the rat popula-
tion could have exceeded 3.1 million.
The evidence from elsewhere in the
Pacific makes it hard to believe that rats
would not have caused rapid and wide-
spread environmental degradation.
But there is still the question of how
much of an effect rats had relative to
the changes caused by humans, who
cut down trees for a number of uses and
practiced slash-and-burn agriculture. I
believe that there is substantial evidence
that it was rats, more so than humans,
that led to deforestation.
Our work on Anakena, as well as
previous archaeological studies, found
thousands of rat bones. It seems that the
Polynesian rat population grew quickly,
then fell more recently before becoming
extinct in the face of competition from rat
species introduced by Europeans. Almost
all of the palm seed shells discovered
on the island show signs of having been
gnawed on by rats, indicating that these
once-ubiquitous rodents did affect the
Jubaea palm’s ability to reproduce. Reason
to blame rats more than people may also
be revealed in the analysis of sediments
obtained at Rano Kau, which, like the
Hawaiian evidence, appears to show that
the forest declined (leaving less forest pol-
len in the sediment) before the extensive
use of fire by people.
A Misplaced Metaphor?
By the time the second round of radio-
carbon results arrived in the fall of 2005,
a complete picture of Rapa Nui’s pre-
history was falling into place. The first
settlers arrived from other Polynesian
islands around 1200 a.d. Their numbers
grew quickly, perhaps at about three per-
cent annually, which would be similar to
the rapid growth shown to have taken
place elsewhere in the Pacific. On Pit-
cairn Island, for example, the population
increased by about 3.4 percent per year
following the appearance of the Bounty
mutineers in 1790. For Rapa Nui, three
percent annual growth would mean that
a colonizing population of 50 would
have grown to more than a thousand
in about a century. The rat population
would have exploded even more quick-
ly, and the combination of humans cut-
ting down trees and rats eating the seeds
would have led to rapid deforestation.
Thus, in my view, there was no extended
period during which the human popula-
tion lived in some sort of idyllic balance
with the fragile environment.
It also appears that the islanders be-
gan building moai and ahu soon after
reaching the island. The human popu-
lation probably reached a maximum
of about 3,000, perhaps a bit higher,
around 1350 a.d. and remained fairly
stable until the arrival of Europeans.
The environmental limitations of Rapa
Nui would have kept the population
from growing much larger. By the time
Roggeveen arrived in 1722, most of the
island’s trees were gone, but deforesta-
tion did not trigger societal collapse, as
Diamond and others have argued.
There is no reliable evidence that the
island’s population ever grew as large
as 15,000 or more, and the actual down-
fall of the Rapanui resulted not from
internal strife but from contact with Eu-
ropeans. When Roggeveen landed on
Rapa Nui’s shores in 1722, a few days
after Easter (hence the island’s name),
he took more than 100 of his men with
him, and all were armed with muskets,
pistols and cutlasses. Before he had ad-
vanced very far, Roggeveen heard shots
from the rear of the party. He turned
to find 10 or 12 islanders dead and a
number of others wounded. His sailors
claimed that some of the Rapanui had
made threatening gestures. Whatever
the provocation, the result did not bode
well for the island’s inhabitants.
Newly introduced diseases, conflict
with European invaders and enslave-
ment followed over the next century
and a half, and these were the chief
causes of the collapse. In the early 1860s,
more than a thousand Rapanui were
taken from the island as slaves, and by
the late 1870s the number of native is-
landers numbered only around 100. In
1888, the island was annexed by Chile.
It remains part of that country today.
In the 1930s, French ethnographer Al-
fred Metraux visited the island. He later
described the demise of Rapa Nui as
“one of the most hideous atrocities com-
mitted by white men in the South Seas.”
It was genocide, not ecocide, that caused
the demise of the Rapanui. An ecological
catastrophe did occur on Rapa Nui, but
it was the result of a number of factors,
not just human short-sightedness.
I believe that the world faces today an
unprecedented global environmental cri-
sis, and I see the usefulness of historical
examples of the pitfalls of environmental
destruction. So it was with some unease
that I concluded that Rapa Nui does not
provide such a model. But as a scientist
I cannot ignore the problems with the
accepted narrative of the island’s prehis-
tory. Mistakes or exaggerations in argu-
ments for protecting the environment
only lead to oversimplified answers and
hurt the cause of environmentalism. We
will end up wondering why our simple
answers were not enough to make a dif-
ference in confronting today’s problems.
Ecosystems are complex, and there
is an urgent need to understand them
better. Certainly the role of rats on Rapa
Nui shows the potentially devastating,
and often unexpected, impact of inva-
sive species. I hope that we will continue
to explore what happened on Rapa Nui,
and to learn whatever other lessons this
remote outpost has to teach us.
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Bahn, P. G., and J. R. Flenley. 1991. Easter Island,
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Butler, K., C. A. Prior and J. R. Flenley. 2004.
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Island. Radiocarbon 46(1):395–405.
Diamond, J. 1995. Easter’s end. Discover 9:62–69.
Diamond, J. 2005. Collapse: How Societies Choose
to Fail or Succeed. New York: Viking.
Hunt, T. L., and C. P. Lipo. 2006. Late coloniza-
tion of Easter Island. Science 311:1603–1606.
Lipo, C. P., and T. L. Hunt. Mapping prehis-
toric statue roads on Easter Island. Antiquity
79:158–168.
Mann, D., J. Chase, J. Edwards, R. Beck, R. Rean-
ier and M. Mass. 2003. Prehistoric destruction
of the primeval soils and vegetation of Rapa
Nui (Isla de Pascua, Easter Island). In Easter
Island: Scientific Exploration into the World’s
Environmental Problems in Microcosm, ed. J.
Loret and J. T. Tanacredi. New York: Kluwer
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For relevant Web links , consult this
issue of Amer ican Scientist Online :
http ://www.americanscientist .org/
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Chapter
Reshaping Environments: An Interdisciplinary Approach to Sustainability in a Complex World draws together a team of specialist authors from disciplines including urban planning, social sciences, engineering and environmental science to examine the diverse influences humans have upon the natural environment. This interdisciplinary approach presents multifaceted responses for complex environmental issues. The book explores current environmental science theories to provide a solid foundation of theoretical knowledge. Drawing on a range of case studies, it develops core analytical skills for application to real-world environmental issues. Reshaping Environments gives environmental science students the tools and insight to comprehend the range of influences society imposes on the natural environment. It is essential reading for those interested in creating a mutually beneficial future for human society and the natural environment.
Chapter
Reshaping Environments: An Interdisciplinary Approach to Sustainability in a Complex World draws together a team of specialist authors from disciplines including urban planning, social sciences, engineering and environmental science to examine the diverse influences humans have upon the natural environment. This interdisciplinary approach presents multifaceted responses for complex environmental issues. The book explores current environmental science theories to provide a solid foundation of theoretical knowledge. Drawing on a range of case studies, it develops core analytical skills for application to real-world environmental issues. Reshaping Environments gives environmental science students the tools and insight to comprehend the range of influences society imposes on the natural environment. It is essential reading for those interested in creating a mutually beneficial future for human society and the natural environment.
Chapter
Reshaping Environments: An Interdisciplinary Approach to Sustainability in a Complex World draws together a team of specialist authors from disciplines including urban planning, social sciences, engineering and environmental science to examine the diverse influences humans have upon the natural environment. This interdisciplinary approach presents multifaceted responses for complex environmental issues. The book explores current environmental science theories to provide a solid foundation of theoretical knowledge. Drawing on a range of case studies, it develops core analytical skills for application to real-world environmental issues. Reshaping Environments gives environmental science students the tools and insight to comprehend the range of influences society imposes on the natural environment. It is essential reading for those interested in creating a mutually beneficial future for human society and the natural environment.
Chapter
Reshaping Environments: An Interdisciplinary Approach to Sustainability in a Complex World draws together a team of specialist authors from disciplines including urban planning, social sciences, engineering and environmental science to examine the diverse influences humans have upon the natural environment. This interdisciplinary approach presents multifaceted responses for complex environmental issues. The book explores current environmental science theories to provide a solid foundation of theoretical knowledge. Drawing on a range of case studies, it develops core analytical skills for application to real-world environmental issues. Reshaping Environments gives environmental science students the tools and insight to comprehend the range of influences society imposes on the natural environment. It is essential reading for those interested in creating a mutually beneficial future for human society and the natural environment.
Chapter
Reshaping Environments: An Interdisciplinary Approach to Sustainability in a Complex World draws together a team of specialist authors from disciplines including urban planning, social sciences, engineering and environmental science to examine the diverse influences humans have upon the natural environment. This interdisciplinary approach presents multifaceted responses for complex environmental issues. The book explores current environmental science theories to provide a solid foundation of theoretical knowledge. Drawing on a range of case studies, it develops core analytical skills for application to real-world environmental issues. Reshaping Environments gives environmental science students the tools and insight to comprehend the range of influences society imposes on the natural environment. It is essential reading for those interested in creating a mutually beneficial future for human society and the natural environment.
Chapter
Reshaping Environments: An Interdisciplinary Approach to Sustainability in a Complex World draws together a team of specialist authors from disciplines including urban planning, social sciences, engineering and environmental science to examine the diverse influences humans have upon the natural environment. This interdisciplinary approach presents multifaceted responses for complex environmental issues. The book explores current environmental science theories to provide a solid foundation of theoretical knowledge. Drawing on a range of case studies, it develops core analytical skills for application to real-world environmental issues. Reshaping Environments gives environmental science students the tools and insight to comprehend the range of influences society imposes on the natural environment. It is essential reading for those interested in creating a mutually beneficial future for human society and the natural environment.
Chapter
Reshaping Environments: An Interdisciplinary Approach to Sustainability in a Complex World draws together a team of specialist authors from disciplines including urban planning, social sciences, engineering and environmental science to examine the diverse influences humans have upon the natural environment. This interdisciplinary approach presents multifaceted responses for complex environmental issues. The book explores current environmental science theories to provide a solid foundation of theoretical knowledge. Drawing on a range of case studies, it develops core analytical skills for application to real-world environmental issues. Reshaping Environments gives environmental science students the tools and insight to comprehend the range of influences society imposes on the natural environment. It is essential reading for those interested in creating a mutually beneficial future for human society and the natural environment.
Chapter
Reshaping Environments: An Interdisciplinary Approach to Sustainability in a Complex World draws together a team of specialist authors from disciplines including urban planning, social sciences, engineering and environmental science to examine the diverse influences humans have upon the natural environment. This interdisciplinary approach presents multifaceted responses for complex environmental issues. The book explores current environmental science theories to provide a solid foundation of theoretical knowledge. Drawing on a range of case studies, it develops core analytical skills for application to real-world environmental issues. Reshaping Environments gives environmental science students the tools and insight to comprehend the range of influences society imposes on the natural environment. It is essential reading for those interested in creating a mutually beneficial future for human society and the natural environment.
Chapter
Reshaping Environments: An Interdisciplinary Approach to Sustainability in a Complex World draws together a team of specialist authors from disciplines including urban planning, social sciences, engineering and environmental science to examine the diverse influences humans have upon the natural environment. This interdisciplinary approach presents multifaceted responses for complex environmental issues. The book explores current environmental science theories to provide a solid foundation of theoretical knowledge. Drawing on a range of case studies, it develops core analytical skills for application to real-world environmental issues. Reshaping Environments gives environmental science students the tools and insight to comprehend the range of influences society imposes on the natural environment. It is essential reading for those interested in creating a mutually beneficial future for human society and the natural environment.
Chapter
Reshaping Environments: An Interdisciplinary Approach to Sustainability in a Complex World draws together a team of specialist authors from disciplines including urban planning, social sciences, engineering and environmental science to examine the diverse influences humans have upon the natural environment. This interdisciplinary approach presents multifaceted responses for complex environmental issues. The book explores current environmental science theories to provide a solid foundation of theoretical knowledge. Drawing on a range of case studies, it develops core analytical skills for application to real-world environmental issues. Reshaping Environments gives environmental science students the tools and insight to comprehend the range of influences society imposes on the natural environment. It is essential reading for those interested in creating a mutually beneficial future for human society and the natural environment.
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The largest volcanic crater on Easter Island in the South Pacific contains a lake 1 km in diameter with large floating mats of vegetation, mainly Scirpus californicus . A core taken through a mat near the center produced anomalous dates, with older dates above younger ones. The possibility that the mat had become inverted was considered, but palynological evidence refutes this idea because it shows a progressive upward decline of forest pollen, which is well known from other swamp cores on the island. A new series of radiocarbon dates made directly on pollen concentrates was obtained. These dates also produced inconsistencies, particularly when pollen concentrate ages were compared with 14 C ages on plant fragments from the same depth. This series of 14 C ages seems to indicate that both old and young organic components in the sediment are deposited contiguously and that the depositional history of these cores is more complex than previously known. Previous age determinations on bulk sediments from Easter Island, which also show anomalous dates, may be too simplistic. This paper provides a warning to other researchers dating sediments from Easter Island. We suggest that sample selection and dating procedures be carefully considered for these sediments.
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Traditional knowledge and the earliest archaeological 14C date suggest that people arrived on Rapa Nui as early as A.D. 400 (Smith, 1961; Heyerdahl and Ferndon, 1961; Ayers, 1971; Bahn and Flenley, 1992). Prior to human arrival, much of the island was probably forested, with the largest trees a now-extinct species of palm (Flenley et al., 1991). Between A.D. 1000 and 1700, the Rapa Nui people erected megalithic sculpture, may have used a written language, and possibly numbered > 10,000 people (Bahn, 1993). However, when James Cook visited Rapa Nui in 1774, he found only several thousand people eking out a living amidst ruins on an island barren of trees. In a hypothesis originated by Mulloy (1970) and fully developed by Flenley and King (1984), Flenley et al (1991), and Bahn and Flenley (1992), uncontrolled population growth destroyed the natural vegetation, degraded the island’s ecosystems, and eventually led to the near extinction of the human population. This putative ecological history of Easter Island is cited as support for predictive models for the human use of natural resources (Brander and Taylor, 1998) and has passed into the modern folklore embodied by popular cinema. Accepting that Rapa Nui is a microcosm for the planet Earth, the “Lost Eden” interpretation of its history paints a grim picture of our collective future (Bahn and Flenley, 1992). On the other hand, the paleoecological data that describes the ecological history of Rupa Nui is far from complete (Orlic and Orliac, 1998; Nunn, 2000).
Article
Full-text available
The largest volcanic crater on Easter Island in the South Pacific contains a lake 1 km in diameter with large floating mats of vegetation, mainly Scirpus californicus. A core taken through a mat near the center produced anomalous dates, with older dates above younger ones. The possibility that the mat had become inverted was considered, but palynolog- ical evidence refutes this idea because it shows a progressive upward decline of forest pollen, which is well known from other swamp cores on the island. A new series of radiocarbon dates made directly on pollen concentrates was obtained. These dates also produced inconsistencies, particularly when pollen concentrate ages were compared with 14C ages on plant fragments from the same depth. This series of 14C ages seems to indicate that both old and young organic components in the sediment are deposited contiguously and that the depositional history of these cores is more complex than previously known. Previous age determinations on bulk sediments from Easter Island, which also show anomalous dates, may be too simplistic. This paper provides a warning to other researchers dating sediments from Easter Island. We suggest that sample selection and dating pro- cedures be carefully considered for these sediments.
Book
The ruined cities, temples, and statues of history's great, vanished societies (Easter Island, Anasazi, the Lowland Maya, Angkor Wat, Great Zimbabwe and many more) are the birthplace of endless romantic mysteries. But these disappearances offer more than idle conjecture: the social collapses were due in part to the types of environmental problems that beset us today. Yet many societies facing similar problems do not collapse. What makes certain societies especially vulnerable? Why didn't their leaders perceive and solve their environmental problems? What can we learn from their fates, and what can we do differently today to help us avoid their fates?