The charismatic great blue heron, at about four feet in height and a wingspan of about six feet, is the largest heron in North America. This bluish-gray, long-legged wader is a common resident of the Mississippi National River and Recreation Area, where it can be seen stalking prey along the river and the edges of shallow floodplain lakes.
The blue heron is well suited to finding and catching fish. A patient hunter, the blue heron hunts by wading slowly in shallow water where it finds crayfish, fish, small turtles, leeches, aquatic insects, and frogs. Its bill is pointed and serrated, which makes it well suited to stab and grip its slippery prey. It may also hunt for small animals, such as mice, and large insects in grasslands and fields.
Great blue herons nest in treetop "colonies," sometimes also called "heronries." Colonies may consist of a few nests but some are much larger. Nests are generally located 30-70 feet above the ground or water in large trees, which often stand in water or on an island. Such a location may reduce nest predation by land-based predators. Nesting in colonies also increases the number of sharp eyes looking for dangerous predators.
There is a white color phase of the blue heron called a "great white heron," but it's range is limited to Florida and it isn't found in Minnesota. If you spot a large, heron-like bird that is white in the park, it is most likely a great egret.