(terms derived from "least") * at least * last but not least * least bittern * least common denominator * least flycatcher * least of all * least resistance * least sandpiper * least shrew * least upper bound * least weasel * log-linear least-squares method * method of least squares * not the least bit * path of least resistance * to say the least American Bittern: Medium, secretive, heron-like wading bird with stout body and neck, and relatively short legs. ... American Bittern. Upperparts are streaked brown and buff and underparts are white with brown streaks. Only 30 cm in length, it is no larger than an American Robin. Least bittern definition is - a small American bittern (Ixobrychus exilis) that is largely black above with chestnut or yellowish brown sides fading to white below. Throat is white with black slashes on sides of neck. The Least Bittern is smaller, lacks the bold, checkered pattern on the back of the American Bittern. Least bittern definition is - a small American bittern (Ixobrychus exilis) that is largely black above with chestnut or yellowish brown sides fading to white below. The American Bittern, B. lentigrosus, is not quite as restricted to reed beds as is the Eurasian species and can be observed in less concealing wetland habitats. Most of what follows is based on a very thorough 1996 research paper by Ron Pittaway and Peter Burke (see References below). An American Bittern in Argyle, Nova Scotia. The Least Bittern breeds in wetland areas throughout the eastern U.S. and along the Pacific coast, and in scattered localities in the western states, Mexico, the Caribbean, and Central and South America. Herons and bitterns have binocular vision and are able to see prey easily through water, sometimes shading the area with their bodies. Usually seen perched motionless, straddling reeds at the edge of water or on a short dash flying just above the reeds. I've never even seen a Least Bittern--well, not enough of a glimpse to even hope for a photo. Climate threats facing the American Bittern. Like the more familiar American Bittern, the Least Bittern hunches at rest and freezes when alarmed, with its bill stretched skyward. Strong direct flight with deep rapid wing beats. There are two species of bitterns seen in North America, they are the American Bittern and the Least Bittern. Least Bittern. The Yellow Bittern, is a vagrant from Asia, that has been spotted. veys at Lacreek National Wildlife Refuge, South Dakota, 2002-2003, by species and year. The Least Bittern is the smallest member of the heron family in North America. I've been to places where I *know* there were some, but they are really good at hiding out. Yellow-crowned Night-Heron. It is migratory visiting as far north as Canada during the summer. Similar Species. Gallery of american bittern pictures submitted by photographers. Animals Membership Science Education Support Smithsonian Migratory Bird Center Declines in Montana and the species specialized habitat requirements warrant general concern about the persistence of the species.