An adaptable bird whose large size enables it to feed on a variety of prey-from large fish and frogs to mice, small birds, and insects-the Great Blue has one of the widest ranges of any North American heron. This wide choice of food enables it to remain farther north during the winter than other species, wherever there is open water, although such lingering birds may fall victim to severe weather. Most Great Blues nest in colonies in tall trees; their presence is often unsuspected until the leaves fall and the groups of saucer-shaped nests are exposed to view. In late summer young herons disperse widely and may be encountered at small ponds, in mountain waters, or even in backyard pools-wherever fish are plentiful.