One of my first encounters was in the Adirondacks on a Memorial Day canoe trip. At the end of the first day paddling up the Oswegatchie, we pulled into a lean-to and set up camp for the night. After dinner, we took the canoe for a short spin through a nearby flat wetland where we heard the distinctive guttural "pump-er-lunk" call.
We never saw that American Bittern because they are secretive and well camouflaged. In size they are intermediate between the small Green Heron and the larger Great Blue Heron. The back is smudgy brown and the front is heavily streaked. Their first defense is to freeze with the bill in the air – something called the "reed pose" (see the photo at right, taken from the auto tour route at Montezuma NWR). The stripes help it blend into the vegetation, usually cattails. Their legs are relatively short for a wading bird, and if you see them, you might notice they’re green.
Bitterns eat a variety of small animals including insects, snakes, amphibians, crayfish, fish and small mammals. We once watched a bittern grab a snake which immediately wrapped itself around the birds’ bill and neck. The struggle lasted until the bittern suffocated the snake and ate it.
The American Bittern nests in freshwater wetlands with dense emergent vegetation like cattails, bulrushes and reeds. The nest is built on the ground or a raised tussock surrounded by water. In Wayne County the most likely habitats are along Lake Ontario from Sodus Bay eastward through the Lakeshore Marshes and also in the Montezuma Marshes and Wetlands Complex. Have any of you actually seen young bitterns in any of these areas?
In New York, this American Bittern is listed as a "Species of Special Concern" because it is uncommon and declining in the western and southern portions of the state. Many suitable wetlands have been lost to draining or filling, sometimes unintentionally by siltation. Wetlands are also lost to invasive species like Purple Loosestrife and Phragmites (Tall Reed). Chemical pesticide runoff from surrounding uplands may reduce the potential food supply. Fertilizer runoff leads to eutrophication and choking algae blooms.
Preservation of wetland marshes, 25 acres or larger, with dense patches of native plants will benefit the bittern and many other species adapted to this type of habitat. Switching from chemical pesticides to Integrated Pest Management (IPM) practices will better protect food supplies at the base of the food chain. Conservation easements, usually held by land trusts, can be used to protect existing wetlands and may provide tax benefits. Wide vegetative buffers around the wetlands will help protect breeding habitat and discourage nest predators.
Additions, anecdotes and corrections to this article are welcomed; send to The Northeast Naturalist.
The Green Heron (Butorides virescens) was once known as the Little Green Heron, in reference to its relative size, but the joke became “it’s called that because there is so little green on it.” Green-backed Heron was another name it once held, and that is a little closer to its appearance. In bright sunlight, the back is dark grayish-green. Adults are gray underneath with rufous necks, streaked throats and dark crowns. [The adult at left was photographed at the edge of the Old Erie Canal in the Montezuma Wetlands east of Clyde.] Young birds are more streaked on the neck and throat. As the birds age, the legs change from yellow-green to yellow and then finally orange on adults during breeding season.
At 18 inches long, it is small for a heron, but large compared to most birds we see regularly. It is the length of a crow, but the heron’s wings are much shorter. Seen flying overhead, on its way to the next swamp or back to its nest, the heron might be mistaken for a crow, but there are subtle differences. The heron often travels alone in a straight line, deliberately heading for its next destination. Crows are likely to travel in noisy flocks that swoop and turn as they decide where to go. I’ve seen only crows harassing and chasing raptors, so at a distance, that rules out herons.
Being shorter legged than other waders, the Green Heron prefers to hunt by walking down a fallen log that dips into the water at the lower end. There the bird crouches and waits for a small fish or sometimes a frog. The Green Heron is one of a growing list of animals observed using tools (inanimate objects that make a job easier or more efficient). In the case of the heron, it uses food pellets, cereal, feathers or short sticks dropped on the water to lure fish close enough to catch. The heron also might be found perched on the branch of a tree overhanging the edge of a stream or pond. If it sees you first, it retracts its neck until the head seems to touch the shoulders. Looking like a burl on the limb, the smaller posture helps it hide. As a last resort, the heron leaps into the air with a loud “kee-ow” or “skow” and flies off.
Most herons nest in colonies, but not the Green. Each pair nests by itself, sometimes far from water. One spring, I watched two adults raise their family in the top of a tall spruce plantation about a mile from the river where they went to hunt for food. I haven’t been back during the spring or summer, but assuming the birds returned, life probably got easier for them when a pond was built nearby.
Questions, corrections, anecdotes and suggestions may be sent to The Northeast Naturalist.