Masters of mimicry, spotting the American bittern makes for challenging game, but spring provides a way
By Susan Campbell
There is a large wading bird that calls the marshes of North Carolina’s southeastern coast home, yet — unless you search for it — it is likely to go unnoticed. Not rare, the American bittern is simply secretive and extremely well-camouflaged. However, in the spring, when males become territorial, their booming calls give them away.
American bitterns stand an impressive 3 feet tall on long green legs, and sport rich brown and white plumage. Feathers on the wings are intricately patterned, and the throat and breast are broadly striped. This results in superb camouflage within the habitat that they inhabit. A large head and long bill make them terrifically adaptable predators, being able to hunt an array of creatures from insects to small fish to eels, crayfish and larger frogs, as well as voles and mice. Bitterns are extremely patient as they stalk their prey, moving through the tall vegetation ever so slowly. Furthermore, their eyes are positioned to look down, enhancing their ability to spot their next meal, but this gives them an odd cross-eyed appearance.
Numerous in our area from fall to winter, American bitterns arrive from the North to take advantage of the open water that they require during the colder months. Even so, they lurk in shallow wetlands with dense stands of grasses and rushes where they are impossible to spot. If flushed, individuals fly on a low and direct path to inevitably another hidden spot in the marsh. Should an individual be disturbed or threatened, it will freeze with its bill pointing skyward and sway slightly, mimicking the surrounding vegetation. Interestingly, this habit is so ingrained that bitterns will automatically adopt this posture even if they happen to be in the open. This is most likely to occur during the cooler months, during migration or the wintering grounds, where individuals may forage in drier grasslands.
At this time of year, spotting an American bittern is more possible as males give themselves away by advertising breeding territories. Listen for their odd “bloonk adoonk” vocalizations. They are extremely aggressive now and may be drawn to one another from over a thousand feet apart. Males will face off, displaying plumes on their shoulders, and often spar in the air. Females are attracted by the males’ calls and, if impressed, will allow copulation. However, unlike many other wader species, males will play no role in family rearing. Nests may be placed in the territory of a male, purportedly so that would-be predators are distracted by their “booming.”
American bitterns are usually solitary other than during migration, when they will form small flocks. This factor, as well as their cryptic coloration and slow lifestyle, makes them hard to find, not to mention study. As a result, they are not well-understood. It is, however, agreed that their numbers are declining across their range. Given the precipitous loss of freshwater habitat across North America, it should come as no surprise. Therefore, conservation and restoration efforts of inland marshes, by Ducks Unlimited in North Carolina and across the U.S., and locally by the North Carolina Coastal Federation, are critical for the health of American bittern populations now and in the future.
Susan would love to receive your wildlife sightings and photos at firstname.lastname@example.org.