From watching robins yank worms out of the soil, to kingbirds snatching dragonflies in the air, to a Swainsons Hawk dismembering a gopher on a post. In our minds there is nothing that matches observing the Great Blue Heron in hunting mode. Standing 4.5 feet in height, blessed with a 6-inch harpoon-like bill., as well as having specially evolved neck vertebrae – the heron is a hunting machine. Of interest is the neck vertebrae which creates a “s” shape that allows the heron to snap its neck deep into the water or in the air to catch its prey at lightening fast speeds. Its enormous patience, striking accuracy and excellent 24 hour a day eyesight, all coordinate magnificently to ensure a meal. Known for being a consumer of fish, herons will also eat insects, small mammals, and have been known to enjoy the odd gopher.
A local birding spot, Weed Lake, located in east Langdon on the Glenmore Trail, has a very comfortable metal bench a mere few feet from the water, where birders get a front row seat to enjoy nature. One heron is a frequent visitor out in front of this small point of land. Weed Lake has an abundance of an invasive species of fish, the Prussian Carp. With water mere inches deep, the heron waits for motion in the water . Our shared anticipation of seeing a heron strike quickly to catch a carp keeps us silent while “benched” with cameras at the ready.
A heron tips a birder with some physical clues to indicate an impending strike. The heron’s neck is stretched out and the entire heron freezes into place. At just the right moment the blade-like bill, at an incredible speed, plunges into the water. Rewarded, the heron prepares its catch for ingestion. Fish in particular, enter the digestive tract of a heron in a specific way. If a fish is held sideways in its bill, the heron will take the time to turn the fish so that it can be swallowed head first. Prussian Carp have large scales. Easing the trip downward to the acid filled stomach is done by positioning the fish’s head to enter the dark abyss, followed by the rest of the soon-to-be carcass. The scales then are not a hindrance when swallowed whole in this position. Herons have a loose digestive tract with a highly flexible esophagus and stretchable stomach, a stomach that can drop past the heron’s cloaca if the meal is heavier.
Although there is a stately manner in which the heron appears to conduct itself, be prepared for its hunting behavior. Limit your blinking, lest you miss the incredible millisecond in which a new meal is captured. Thinking back to a canoe trip on Crane Lake in northeastern Alberta almost 20 years ago, this visual marvel involved the misfortune of a northern pike, nabbed in the bulrushes and easily swallowed by the heron. The reality of nature certainly includes the ways of the heron.
-Don Cassidy
