In recent years, stately great blue herons have several nesting rookeries in wooded swamps, near bodies of water where they readily catch fish and other prey, scattered throughout the Middle Atlantic States where they are common, year-round residents. This large species of herons creates colonies of bulky, stick nurseries in the tops of several neighboring deciduous trees, often two or three nests in a tree, in that type of habitat. Great blues create their nesting colonies where they do because of handy food sources to quickly shuttle food to their young. These herons begin their breeding season about the middle of March and use the same stick, treetop cradles year after year.
It's interesting and inspiring to see these majestic herons flying ponderously into their nesting rookeries and to their individual nurseries with sticks and twigs in their beaks and weave those materials into the rims of their nests. Each female great blue lays about four eggs in her cradle and both members of each pair take turns incubating the eggs. Setting birds are hard to see in the nest because they are gray like the sticks and hunkered down in the cradle.
Great blue herons don't always have their rookeries to themselves, however. A pair or two of great horned owls, red-tailed hawks or bald eagles, all of which begin nesting in January, usurp a heron nursery or two, which were built in previous years, in some heron rookeries. A few of the eagles will even prey on some of the herons when they return to their nurseries in March.
Standing over four feet tall and being long-legged and long-necked, great blues are always intriguing to experience. They are magnificent birds in the way they walk, stalk prey in the water and fly. Being large, they are often easy to spot fishing in many larger, more open waterways and impoundments, but not always because of their gray, camouflaging plumage.
Great blue herons are adaptable and real survivors wherever there are waterways and impoundments. They have a varied diet of aquatic creatures and land-based ones. They carefully stalk on their long legs and catch fish, large and small, frogs, tadpoles, water insects and other aquatic critters by throwing out their lengthy necks and beaks.
Great blues are also adept at snaring goldfish and koi from backyard goldfish/koi ponds, much to the horror of many owners. One early March about five years ago, we were victims of a great blue catching all but one of our goldfish. I think the heron was migrating north and either spent a night in one of our tall Norway spruce trees and saw the pond with orange fish the next morning or it raided the pond first and later spent the night in a spruce. Anyway, that heron was around for a few days between the time our fish disappeared to the time I saw that tall, feathered bandit soar into one of our spruces to spend yet another night before moving on.
Interestingly, great blues are also good at catching field mice in cow pastures that have a stream or brook running through them. The herons stalk the mice slowly and carefully, as they creep up on fish, then suddenly lunge their necks and bills forward to grab the mice in their long, sharp beaks. Of course the mice are furry and great blues are used to swallowing slippery prey, which would make swallowing a dry mouse difficult. But the great blues have solved that problem by dunking the mouse in a nearby brook, stream or pond to slick the fur, making ingesting the prey much easier. I've seen them do that several times over the years. Great blues gulp the mice down whole and headfirst, as they do with all their victims.
Great blue herons are also interesting birds in that they hunt prey animals by day and at night. And between feeding forays in winter they stand tall, gray and hunched-up in corn stubble, as they do in wind-beaten cattail marshes.
Big, handsome birds, great blue herons are common most everywhere there are waterways and impoundments in the Mid-Atlantic States, as elsewhere throughout much of North America. Many people enjoy seeing these stately birds in watery habitats, except those folks who have lost goldfish or koi to these adaptable, long-legged marauders.
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