**6. Conclusion**

*Pleistocene Archaeology - Migration, Technology, and Adaptation*

stone-poor, shell-rich island environment of Okinawa.

**5. Plastic behavior in the utilization of animal resources**

hunter-gatherers to live on relatively small islands for a long time.

Okinawa Island, a stone-poor region. At present, it is about 2 km inland from the nearest coast, and it was 5–6 km away from the coast around 20,000–23,000 years ago. Therefore, the Paleolithic people of Sakitari Cave were able to access the coast easily and collect shells and other marine products such as fish. The unique material culture of Sakitari Cave was suitable for the island environment, and it represents the behavioral plasticity of the Paleolithic people and their capacity to adapt to the

The behavioral plasticity of Paleolithic people is observable in their material culture and hunting-gathering actions. The Paleolithic people in Sakitari Cave mostly consumed freshwater crabs (Japanese mitten crab) and freshwater snails. They also ate small vertebrates such as mice, birds, lizards, snakes, frogs, and fish (freshwater and marine). The food waste in Sakitari indicates that small, nocturnal animals living in or near the river were dominant. As in the general example of island fauna, the fauna of Okinawa Island lacks large terrestrial mammals (**Figure 5**). At the first stage of human arrival, there were two species of middle- or small-sized deer and one species of a middle-sized tortoise [33], but they went extinct probably earlier than 30,000 years ago [42, 54]. Based on the limitedness of the terrestrial fauna, some researchers theorize that Paleolithic people were unable to maintain their population on the small island [61, 62]. However, research of the Sakitari remains revealed that the Paleolithic people maintained their population for nearly 20,000 years by consuming small, aquatic animals, which generally are highly reproductive and densely inhabited the area compared to large and middle-sized mammals. This unique, effective use of animal resources enabled the Paleolithic

The extensive consumption of marine resources was reported in ISEA [19, 23–26]. Paleolithic immigrants who came to this area developed diverse fishing and shellfishing

**140**

**Figure 5.**

*Terrestrial and freshwater animals of Okinawa Island.*

Paleolithic people immigrated to the Ryukyu Islands more than 36,000 years ago. Morphological and genetic studies of Paleolithic human fossils from this area have indicated that they probably came through Southeast Asia in the course of the worldwide dispersal of early modern humans. The common use of shell tools including fishhooks and the remarkable consumption of aquatic resources as foods by Paleolithic Ryukyu Islanders suggest the relation to the ISEA.

However, Paleolithic Okinawan culture was unique in dominance of marine shell artifacts and biased consumption of freshwater animals. This unique lifestyle adapted to the stone-poor and shell-rich environment of the island, where there were limited terrestrial animals. The adaptive lifestyle on Okinawa, which is a relatively small oceanic island, suggests the plasticity of Paleolithic people's behavior. Their behavioral plasticity may be one of the driving forces that enabled *Homo sapiens* to migrate to various environments all over the world.

*Pleistocene Archaeology - Migration, Technology, and Adaptation*
