Climatic change and diet of the pre-Hispanic population of Gran Canaria (Canary Archipelago, Spain) during the Medieval Warm Period and Little Ice Age

The hard and soft tissue remains of a pre-Hispanic population of the Gran Canaria Island at six different archaeological localities were studied using 14C dating and stable isotope compositions. Radiocarbon dating indicates island occupation ranging from the beginning of the 7th to the mid-14th century. We analyzed the oxygen isotope compositions of apatite phosphate bones of some pre-Hispanic individuals. The oxygen isotope compositions of meteoric water (δ18Ow) show a significant decrease from −2.1 ± 1.5 to −4.4 ± 1.2‰ (VSMOW) from the Medieval Warm Period (MWP) to the Little Ice Age (LIA). This is interpreted to reflect a decrease in air temperature by about 5 ± 3 °C. Archaeological data along with δ13C, δ15N and δ34S values of soft tissue indicate that the pre-Hispanic population from Gran Canaria relied on agriculture throughout the 7th to mid-14th century. However, a significant contribution of seafood to the diet of the pre-Hispanic population is observed at archaeological sites located close to the shore. These results suggest cultural resilience in the pre-Hispanic population of Gran Canaria, reflected in the relative constancy of their diet in light of climate change.