First, foragers broaden their diet breadth to include secondary and tertiary
foods, such as bitter roots and tubers that need to be processed before eating,
fungi, fruit normally eaten by animals, edible leaf buds, shoots and even
difficult-to-digest leaves. Secondly, making use of their mobility, they will
increase their search ranges, move camp and return to areas where they know
of water and food resources. As vegetable foods begin to disappear, animal
foods may also begin to increase in their diet especially smaller creatures
like fish, reptiles, snakes, frogs, turtles, rats, mice and insects. . . . Thirdly,
foragers will move beyond the affected area, assuming the consequences of
climatic variation are localized. Such a move is often predicated on preestablished
social relationships with neighboring groups, who may be distant kin
or historical allies. (2007: 54)