Migration
Migration occurs when living things move from one biome to another. In most cases organisms migrate to avoid local shortages of food, usually caused by winter.
Bird migration is a common thing. The longest known migration of a bird is that of the Arctic Tern, which migrates from the Arctic to the Antarctic and back each year.
Whales, butterflies, moths, and lemmings are also known to migrate. The periodic migration of flocks of locusts is a phenomenon recorded since Biblical times.
Human migrations also happen on the largest scale, in history and in modern times. Seasonal human migration is very common in agricultural cycles.
In archaeology, migrant, population transfer, population genetics. Try the list of peoples at Nomadic people or look under the specific migrating ethnicity that interests you.
