Colonisation is the process in biology by which a species spreads into new areas. The term can be used to describe colonisation on a small scale (i.e. where a species moves into new areas at a particular site, perhaps as a result of a change in conditions) or on a large scale (i.e. where a species expands it range to encompass new areas; here, 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 by human agency. In biology, the range of an species is the geographical area within which that species can be found. ...

Some large-scale notable colonisation events in the 20th Century are listed below.

Birds

• the colonisation of the New World by the Cattle Egret
• the westwards spread of the Collared Dove across Europe
• the colonisation of Britain by the Little Egret

Carte dAmérique, Guillaume Delisle, c. ... Binomial name Bubulcus ibis (Linnaeus, 1758) The Cattle Egret, Bubulcus ibis, is a small white heron. ... Binomial name Streptopelia decaocto (Frivaldszky, 1838) The Eurasian Collared Dove, Streptopelia decaocto, also called the Eurasian Collared-Dove or simply the Collared Dove, is one of the great colonisers of the avian world. ... World map showing Europe (geographically) When considered a continent, Europe is the worlds second-smallest continent in terms of area, with an area of 10,600,000 km² (4,140,625 square miles), making it larger than Australia only. ... Binomial name Egretta garzetta (Linnaeus, 1766) The Little Egret, Egretta garzetta, is a small white heron. ...

Dragonflies

• the colonisation of Britain by the Small Red-eyed Damselfly

Binomial name Erythromma viridulum (Charpentier, 1840) Small Red-eyed Damselfly Erythromma viridulum is a member of the damselfly family Coenagrionidae Appearance The species is a small damselfly, predominantly black with irridescent blue markings. ...

Moths

• the colonisation of Britain by Blair's Shoulder-knot