Great blue herons are big birds, among the biggest we see here in Illinois. They can stand between 3 feet and 4 1/2 feet tall. Their wingspan is even bigger, sometimes more than 5 1/2 feet! Despite their large size, they weigh very little, only between 5 pounds and 6 pounds. Why are they so lightweight? Like all birds, their bones are hollow.
Great blue herons aren’t quite as bright blue as some of our other blue birds, like blue jays and indigo buntings. They are more of a grayish-blue. Both males and females have the same coloring. These big, blue birds are good hunters, using their long, sharp bills to catch almost anything in reach, including insects, fish, amphibians, reptiles, birds and small mammals.