Grey herons are very adaptable and generally thrive in new environments. However, for long-term habitation, they need locations with at least four months of warm weather, which is crucial for egg-laying and chick development. Grey herons also require shallow bodies of water as their primary foraging sites. These water bodies can include saltwater or brackish inlets and estuaries, freshwater rivers, streams, lakes, marshes, and even fish farming aquacultures. Roosting preferences vary by region; many grey herons prefer to roost in the branches near the tops of tall trees. If trees are not available, they may roost in dense brush or undergrowth.