A large bird observed standing absolutely still at the water’s edge, or wading slowly, sometimes taking minutes for each step, is probably a heron. Herons are predators of fresh and salt water shallows, marshes, swamps, mud flats and other wetlands. Found all over the world, they belong to the taxonomic family Ardeidae, which also includes bitterns and egrets.
Typical Features of Herons
Most herons have long legs with long toes, long necks, and long beaks. The most familiar herons are the larger species: the Great Blue Heron in the Americas, the Cocoi in South America, and the Grey Heron of Europe and Asia. The Black-crowned Night Heron is a wide ranging species that frequents human communities and is often photographed.
A typical heron has a dark back and lighter breast. Many have bold markings on the head and neck, and adults often have elegant plumes on the head, neck and breast. The colours of legs, eyes, bills, and the patch of bare skin between the bill and the eye, are brighter in breeding birds during courtship and mating
A heron in flight moves with slow powerful wing beats and holds its head close to its body with the neck in a graceful S-shape. (Storks and cranes, in contrast, fly with the neck outstretched.) Herons can fly great distances and regularly turn up as vagrant herons, far outside their normal range.
Herons can be difficult to identify at any age, and juveniles are particularly confusing. Young birds lack plumes but may still have some down showing. Their bills are shorter, and they lack the graceful movements of their more experienced parents. Experienced bird watchers can often identify a heron by the way it moves.
Heron Feeding Habits
Herons are accomplished hunters and most stalk fish, amphibians, reptiles, insects, and aquatic invertebrates in shallow water. A heron may also run after prey, or fly above it, hover, dip down, and possibly even swim. The night herons hunt at night, while species like the Great Blue Heron feed during the day. A few feed on land, sometimes following large grazing animals or farming equipment in the hope of an easy meal. Others frequent aquaculture sites and garden ponds and come into conflict with people when they steal fish.
Some species of herons lure live prey so they can easily catch it. They may dip the tip of the bill into the water and vibrate it, mimicking an insect fallen into the water, or drop an item like a feather or a small piece of food onto the water surface. Some stir up the bottom with their feet, both to expose prey and lure prey, and the Black Heron creates a patch of shade by spreading its wings, inviting fish into a mock shelter.
Heron Breeding
Most species of herons have one mate each season. They engage in elaborate courtship displays involving postures and calls, then pairs share the tasks of nest building (males typically provide nest-building materials and females construct the nest), incubating eggs, and feeding three to five young.
Heron parents begin incubating eggs before the entire clutch is laid, so chicks hatch days apart. The larger older nestlings have a survival advantage and it’s normal for some of the other nestlings to die before fledging. Herons feed their young by regurgitating food into the nest or into their mouths. Within days to weeks, the young are able to leave the nest and begin hunting on their own.
Heron Rookeries
Though some, like the Black-crowned Night heron, are solitary birds, herons tend to be gregarious and communal. They hunt together, roost together, and nest together in large colonies called heron rookeries. A heron rookery can be home to just a few pairs of breeding herons, or hundreds of pairs. Herons occupy a rookery year after year, but they sometimes move to a new location for various reasons.
Many heron species were once endangered, mostly due to the demand for their beautiful plume feathers as fashion accessories. Efforts at conservation have been successful, but herons in various parts of the world are still threatened by hunting, egg collecting, habitat loss, and culls when they compete with aquaculture for fish.
Sources
Firefly Encyclopedia of Birds. Perrins, Christopher ed. Buffalo: Firefly Books, 2003
"Herons and Egrets." Tan, Ria. www.naturia.per.sg
The Sibley Guide to Birds. Sibley, David Allen. New York, Alfred A. Knopf. 2000.
Rosemary Drisdelle - Rosemary Drisdelle has been published many times as a nonfiction writer and several times as a poet. Her first book, Parasites: Tales of ...
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