A Bad Day to Be a Tadpole
by Wilton Corkern, President
On any given day this time of year a traveler along Bryan Point Road will almost surely see a Great Blue Heron stalking the aquatic creatures in the Accokeek Creek swamp. Everything about this bird is big: its head and body are four feet long; erect, it stands five feet tall; its wingspan is six feet. Even its bill is over five inches long. Yet it is a graceful flier, able to lift its five pound frame straight into the air with a single flap of its massive wings.
These ubiquitous birds are highly adaptable, and despite huge losses of habitat over the past half-century, they have found a way to survive and flourish. In fact, their ancestors were around some 14 million years ago, according to fossil records. For now, their populations seem to be growing all across North America, and are most dense in the east, from the Great Lakes to the Gulf of Mexico.
They nest in trees above swampy areas, usually in large colonies. A few years ago friend and former Trustee Byron Williams arranged for me to visit a nesting colony in a relatively remote area of Charles County. We parked alongside a road followed a narrow trail through dense woods for about a half-mile. “The first thing you notice,” Byron warned, “is the smell.” And then it hit us: the odor from massive amounts of fish-eating bird droppings wafted through the trees. As we approached the edge of the swamp we saw birds flying to and forth overhead. Then, the rookery: About a dozen acres of trees, festooned with hundreds of stick-built nests. Birds came and went, carrying food to noisy nestlings.
The Great Blue Heron is a formidable predator. It eats mostly fish, but may also take amphibians, reptiles, invertebrates, small mammals, and even other birds – all swallowed whole. During the past week I have watched our regular visitor devour several fish, a bullfrog tadpole, and a crayfish. According to the Cornell University ornithology lab, an adult Great Blue Heron can swallow a fish up to a foot long. I have video of this one gobbling down an 8” catfish. There are reports of Great Blues actually choking to death on fish too big to swallow. They feed in swamps, along the edges of water bodies, and even in open fields. A few days ago Mary Bruce and I watched a Great Blue perched in an oak tree in our residential neighborhood watching a neighbor’s coy pond for opportunity.
No less an observer than John James Audubon himself described the heron’s habits:
How calm, how silent, how grand is the scene! The tread of the tall bird himself no one hears, so carefully does he place his foot on the moist ground, cautiously suspending it for awhile at each step of his progress. Now his golden eye glances over the surrounding objects, in surveying which he takes advantage of the full stretch of his graceful neck.Satisfied that no danger is near, he lays his head on his shoulders, allows the feathers of his breast to droop, and patiently awaits the approach of his finned prey. You might imagine what you see to be the statue of a bird, so motionless is it. But now, he moves; he has taken a silent step, and with great care be advances; slowly does he raise his head from his shoulders, and now, what a sudden start! his formidable bill has transfixed a perch, which he beats to death on the ground. See with what difficulty he gulps it down his capacious throat! and now his broad wings open, and away he slowly flies to another station, or perhaps to avoid his unwelcome observers.
[Quoted from the online version of John James Audubon’s Birds of America, available at www.Audubon.org. It is from an 1840 “First Octavo Edition” of Audubon’s complete seven volume text and presents Audubon’s images and original text descriptions as written.]