Great Blue Herons are mostly have a gray and blue body with a brown neck and a dark blue crest on its head. Great Blue Herons have a wingspan of up to about 73 inches 5 feet the underpart of the wings are grayish blue and the top part of the wings are also gray and blue. Great Blue Herons mostly prey on fish but they also eat snakes, birds, lizards, frogs and salamanders they will also hunt small rodents. Great-blue herons live by rivers, marshes, swamps, bayous, lakes and ponds but great blue herons nest mainly in trees in meadows, fields, bayous, swamps and marshes they live throughout the eastern and western united states and Canada.