The great blue heron is a fascinating bird. Though somewhat gangly in physical stature, the bird is graceful in flight, remarkably stealthy when hunting for food, and is beautifully plumaged.
Belonging to the avian order Ciconiiformes, the great blue heron is the largest heron in North America. Indeed, a great blue heron stands nearly 4 feet tall and weighs 6-8 pounds. Their wingspan alone is 6 feet across. Other herons and heron relatives here in Minnesota include the black-crowned night heron, green heron, great egret and American bittern.
Ornithologists and birders refer to herons, their relatives, and the group of birds they belong to as "wading birds." One of their primary methods of hunting for food - whether a bittern, egret or heron - tends to be by walking slowly, or wading, in shallow areas of a wetland, lake, creek or river searching for prey. Or they will stand immobile in the water for long periods of time waiting for something edible to come near.
Over the years, I have enjoyed watching great blue herons stalking the shallows of wetlands, lakes and rivers. I've always been amazed at what efficient hunters they are. Favorite foods include small fish, frogs, salamanders, crayfish, snakes and sometimes ducklings and other baby birds. They will also eat insects and small rodents.
Within their wetland environments, almost undetectable, a great blue heron will slowly lift a leg to step forward. Gingerly, the bird places its extended foot into the water without making a sound. When its eyes focus on an unsuspecting fish, the heron moves only its long neck forward, then down, thereby directing its head and dagger-like bill toward the surface of the water.
Up to this point, the entire act is completed hypnotically slowly. The actual strike, however, is anything but. In an action that could be likened to a lightening strike, the heron stabs quickly, often immersing all or part of its entire head into the water.
Of all the times I have witnessed a great blue heron's lethal strike, I have never seen the bird miss its mark or meal. A heron will have in its bill a flopping fish, will manipulate the hapless prey for proper placement and will flip the fish headfirst into its mouth and swallow it whole.
One would think that such a lanky physique would limit a great blue heron's mobility. However, the big bird can land effortlessly in the limbs of treetops, and, surprisingly, float like a duck in water too deep to wade in.
I remember the first time I saw this latter behavior. While fishing one evening many summers ago, I watched a great blue heron flying across the lake in my direction. I was amazed when the bird began slowing its flight and stretching its legs out below itself. In a not-so-nimble landing, the bird came to a halt, belly first, and floated for several minutes until it apparently felt the need to fly away.
And like many birds, trees offer more than just pleasant places to perch and view their surroundings from. Great blue herons are well known for the large nesting colonies they form with one another. Called rookeries, the sociable herons will return year after year to the same nesting site, often arriving to these areas around the same time every year.
Inside of somewhat flimsy appearing nests comprised of sticks assembled in flat, platform-style structures within the canopies of mature trees, great blue herons generally lay three to five eggs. Both parents share in the duties of incubating the eggs and feeding their growing chicks.
The problem with these large heron rookeries becomes obvious if you should happen to see one up close. Bodily excrement from so many birds concentrated in a relatively confined area usually has a detrimental effect on the vegetation below the rookery. Many trees die, and so the rookery is eventually abandoned and relocated.
It's easy to identify a great blue heron, both in flight and by their distinctive silhouette. Unlike sandhill cranes, which are sometimes confused as great blue herons, or vice versa, herons fly with their necks in an "S" shape with the back of their head essentially resting on their shoulders. Herons will often perch with their necks positioned in a similar manner.
Conversely, sandhill cranes fly with their necks stretched out, much in the way of ducks, geese, and swans. Observing a flying great blue heron gives one the impression that the bird has hardly any neck at all.
My dad used to call great blue herons "slough pumpers." And for many years as a young boy on the farm, I used to think the same thing. Truth is, the moniker belongs to the American bittern. Still, the great blue heron, when flushed from the secrecy of a vegetated wetland or riverbank, croaks astonishingly loud, rivaling the vocal decibels of any "slough pumper."
The great blue heron is one of those birds that you simply can't help but appreciate. With colorful plumage and long, ornate plumes on its head, lower neck, and back during the spring breeding season, the great blue heron is as attractive and elegant a bird as they come. Couple this with large size, long legs and expansive wingspan, the great blue heron is a notable bird to observe as we get out and enjoy the great outdoors.
Blane Klemek is the Bemidji area assistant wildlife manager, DNR Division of Fish & Wildlife. He can be reached at firstname.lastname@example.org