Little egrets colonised the UK from southern Europe in the 1990s and have become an established breeding species. Their welfare as a relatively new colonist depends on productive wetlands and heronry sites.
Little egrets as a colonising species face the welfare challenges of establishing themselves in a novel landscape. Initial colonists must locate suitable nesting sites and foraging habitat without the learned information that long-established populations accumulate through tradition. Nesting colonially provides some protection from predation but also creates competition for optimal nesting positions within the heronry. Cold UK winters can challenge a species adapted to milder European winters, particularly prolonged freezing periods that ice over shallow wetlands and prevent foraging. The success of UK colonisation demonstrates that suitable habitat is available, and that individuals that navigate initial establishment challenges can achieve good welfare outcomes.