Colonisation or colonization is the process in biology by which a species spreads to new areas. Colonisation often refers to successful immigration where a population becomes integrated into a community, having resisted initial local extinction.
One classic model in biogeography posits that species must continue to colonize new areas through its life cycle (called a taxon cycle) in order to achieve [longevity]]. Accordingly, colonisation and extinction are key components of island biogeography, a theory that has many applications in ecology, such as metapopulations.
- The term can be used to describe colonisation on:
- microorganisms on surfaces.
- small scales: colonising new sites, perhaps as a result of environmental change.
- large scales: where a species expands its range to encompass new areas. This can be via a series of small encroachments or by long-distance dispersal. The term range expansion is often used.
The term is generally only used to refer to the spread into new areas by natural means, as opposed to introduction or translocation by humans, which are called introduced species and sometimes becoming invasive species.
Species colonisation events
- Some large-scale notable colonisation events in the 20th Century are:
- the colonisation of the New World by the Cattle Egret
- the colonisation of Britain by the Little Egret
- the colonisation of the East Coast of North America by the Brewer's Blackbird
- the colonisation-westwards spread across Europe of the Collared Dove
- Wilson, E.O. (1962) The nature of the Taxon Cycle in Melanesian ant fauna http://www.zoology.siu.edu/sears/Wilson1961.pdf The American Naturalist