The little egret has successfully colonised Britain since the 1990s, offering insights into natural range expansion and the welfare challenges facing a species adapting to new environments.
The little egret's successful colonisation demonstrates the remarkable adaptive capacity of some species given adequate legal protection. From a welfare perspective, newly colonising populations face particular challenges: unfamiliar prey assemblages, less optimal nesting sites as prime habitat is occupied, and elevated susceptibility to harsh winter weather. The welfare of egrets at the northern edge of their expanding range is particularly precarious during cold snaps, when prey availability in frozen or turbid water drops sharply. Disturbance at nesting colonies causes chick abandonment and adult stress. The experience with little egrets also illustrates the rapid impact hunting can have - a lesson applicable to many threatened species globally.