The first time Christopher Columbus voyaged across the Atlantic, the first people he met were the Taíno, who lived on various islands of the Caribbean. They were a sophisticated agricultural society with large settlements. But their encounter with the Europeans proved fatal, with the civilization vanishing almost completely a few decades later.
In the 1990s, archaeological excavations led to the discovery of a Taíno settlement in Los Buchillones, a shallow lagoon in north central Cuba. Submerged in about a meter of water, Los Buchillones is one of the largest and best-preserved prehistoric settlements discovered so far in the Caribbean. Archaeologists found remains of about 40 dwellings, as well as a variety of wooden and ceramic artifacts.
What surprised scientists, however, was the discovery that Taíno houses were built on stilts. “This was a really important finding,” said Matthew Peros of Bishop’s University, Quebec, Canada, “because up until then, Taíno settlements had not been formally associated with that kind of settlement strategy.”
Solving an Old Puzzle with Sediment
Since the early 2000s, Peros said, archaeologists suspected that the stilt houses may have been an adaptation to climate and environmental change.
With more data available from the region, Peros and his team have been able to test this hypothesis and presented their results in a poster session at AGU’s Fall Meeting 2020. The team reconstructed the past climate of the region using sediment cores from a limestone sinkhole (cenote) called Cenote Jennifer on the island of Cayo Coco, about 16 kilometers north of Los Buchillones. Sediments and organic matter build up in such sinkholes, and geochemical testing can reveal clues that can be used to reconstruct past climate.
The researchers used the sediment core’s oxygen isotope ratios, which reflect evaporation or precipitation, to identify wet and dry periods in the region. They also correlated the oxygen isotope ratios with calcium to titanium ratios, obtained by scanning the sediment core using X-ray fluorescence. This ratio corresponds to deposition of calcium carbonate in the cenote, with drier periods having more calcium deposition. Researchers found the cenote’s oxygen isotope and calcium ratios matched up quite well.
Radiocarbon dating of the sediment core gave the ages of the different sediment layers. Researchers correlated the dates with the isotope analyses and thus obtained climate data from Los Buchillones over the past 2,000 years. In addition, the team used radiocarbon dating of the site’s artifacts and structural remains to give them an idea of the times the village was occupied.
Building Climate Resilience
The data from Cenote Jennifer showed the Los Buchillones region endured two major dry periods, the first between 900 and 1200 CE and the second around 1650 CE, the peak of the Little Ice Age. When the authors matched the climate data with the period when the village was occupied, they found that the stilt village flourished in the wet interval, possibly because conditions were favorable for agriculture and fishing. “So there seems to be a link between climate and actual occupation of the site itself,” said Peros.
Paleoclimate reconstruction of hurricanes from the Bahamas indicated this was also a time when hurricane activity increased in the region. Building houses on stilts may have been a deliberate approach to cope with an active hurricane period, which causes increased storm surges and coastal flooding, Peros said. Although the site was well protected by being built behind a coral reef, stilt houses could have been a backup strategy. “There seems to have been a lot of thought put into building a settlement that is well suited to a dynamic coastal environment,” said Peros.
The Taíno stilt houses were undoubtedly more resilient to storm surges caused by hurricanes, said Isabel Rivera-Collazo, an environmental archaeologist at the University of California, San Diego, who was not part of the research. But she is not completely convinced that these types of houses were a purposeful adaptation to climate change. It is certainly plausible, Rivera-Collazo said, but archaeologists will need to study more examples of historic dwellings to definitively say that the Taíno intentionally constructed buildings as a response to climate change.
—Lakshmi Supriya ([email protected]), Science Writer