Animal migration is the relatively long-distance movement of individuals, usually on a seasonal basis. It is a ubiquitous phenomenon, found in all major animal groups, including birds, mammals, fish, reptiles, amphibians, insects, and crustaceans. The trigger for the migration may be local climate, local availability of food, the season of the year or for mating reasons. To be counted as a true migration, and not just a local dispersal or irruption, the movement of the animals should be an annual or seasonal occurrence, such as birds migrating south for the winter, or a major habitat change as part of their life, such as young Atlantic salmon leaving the river of their birth when they have reached a few inches in size.
Read more about Animal Migration: Definition, Migration Types, Multiple Generation Migration, Human Cultural Responses To Animal Migration
Famous quotes containing the word animal:
“All things are flowing, even those that seem immovable. The adamant is always passing into smoke. The plants imbibe the materials which they want from the air and the ground. They burn, that is, exhale and decompose their own bodies into the air and earth again. The animal burns, or undergoes the like perpetual consumption. The earth burns, the mountains burn and decompose, slower, but incessantly.”
—Ralph Waldo Emerson (1803–1882)