It is not clear whether the Tasmanians were nomadic, moving to new encampments every day or two, or transhumant, moving inland in the warm months and to the sea in the colder months. There is some evidence of regional variation in settlement patterns, with groups in the west being more settled than those in the east. In either case, the location of settlements was determined largely by the availability of food. Tasmanian societies were territorial, and trespass into another group's territory usually led to warfare. Shelters for nomadic groups were windbreaks made from bark, while more settled groups lived in communities of beehive-shaped shelters located along the banks of rivers or lagoons.