Easter Island mystery

Easter Island, a Chilean territory, is a remote volcanic island in Polynesia. Its native name is Rapa Nui. It’s famed for archaeological sites, including nearly 900 monumental statues called moai, created by inhabitants during the 13th–16th centuries. The moai are carved human figures with oversize heads, often resting on massive stone pedestals called ahus. Ahu Tongariki has the largest group of upright moai.
Polynesian people most likely settled on Easter Island sometime between 700 and 1100 AD and created a thriving and industrious culture as evidenced by the island's numerous enormous stone moai and other artifacts. However, human activity, the introduction of the Polynesian rat and overpopulation led to gradual deforestation and extinction of natural resources which severely weakened the Rapa Nui civilization.[4] By the time of European arrival in 1722, the island's population had dropped to 2,000–3,000 from an estimated high of approximately 15,000 just a century earlier. European diseases and Peruvian slave raiding in the 1860s further reduced the Rapa Nui population, to a low of only 111 inhabitants in 1877.