Photo courtesy Keith Bruno
This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the American bittern.
With nicknames that include “thunder-pumper” and “water belcher” (Cornell Lab of Ornithology), the American bittern gets more attention and recognition for its novel and often booming pump-er-lunk vocalizations than from actually being visibly detected. After all, they are masters of the mirage — adept at blending into their surroundings by moving very slowly and sticking up their slender necks and bills to look like a bulrush, cattail or nearby reeds when alarm warrants camouflaging into the landscape. This smaller, compact cousin of great blue herons is an inland mainstay of freshwater marsh and wetland habitat. Both males and females have vertically oriented brown and white stripes along their breast and belly, a notable white eye line, and a distinct long, black patch that emanates from just below the base of their bill and frames an otherwise white throat. Their overall casting is brown.
Their expansive diet includes everything from small fish and amphibians to crustaceans and insects (think water striders and aquatic beetles that frequent the shallows of muddy freshwater wetlands), as well as large terrestrial insects (dragonflies and grasshoppers), small rodents and even snakes on occasion. Hunting behavior is similar to other herons, statuesque at times with success that hinges on slow stalking and deliberate strikes to overcome prey. When it comes to nesting, the females do nearly all of the nest construction, incubation and feeding amidst thick vegetation. Clutches yield two to seven eggs.
Now, in order to see this bird, you’re going to need to do one of two things: (1) visit a regional wildlife refuge or similar marshland complex, ideally during spring, and listen for their otherworldly deep bellows to locate them (then, good luck spotting them) or (2) just get plumb lucky and stumble into them while birding in similar country. The closest known detections to Pagosa Springs are likely some of the individuals that have been seen/heard down in the shallow slack water wetlands on the northern ends of Navajo Lake. Bitterns may migrate when temperatures stay below freezing, as access to shallow water for food sources is critical.
Their survival and reproductive success is inextricably linked to the health and wealth of wetland ecosystems. Many of these complexes have been altered, manipulated or destroyed by development, siltation, contamination, noxious weed invasion or other disturbances. Fortunately, American bittern population numbers have benefited from active efforts to rebuild and replace wetlands where forfeited elsewhere.
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