Long-tailed ducks, formerly known as oldsquaws, nest along rivers, lakes and ponds of the Arctic tundra. Most winter offshore along the Pacific and Atlantic coasts of North America or on the Great Lakes; however, a small number turn up on inland lakes and reservoirs during the colder months.
According to the Colorado Birding Society, about 15 long-tailed ducks have been observed along the Front Range this winter, from the northern Colorado border to Pueblo Reservoir; I had the good fortune to watch three of them on South Platte Reservoir, in southwest Metro Denver, this morning.. Those hoping to observe these attractive visitors must be patient since they often spend more time underwater than on the surface; using their wings for propulsion, long-tailed ducks can dive to 200 feet (more than any other species of waterfowl) and may remain underwater for two minutes (per my observation this morning). During those dives, the ducks feed on bottom vegetation, aquatic invertebrates and small fish.
Molting three times between autumn and spring, long-tailed ducks have variable plumage in the course of a year; males, which sport the long tail for which the species is named, are more white in winter and darker in summer. These sea ducks are also known for their varied cackles and yodeling that peak in winter, when mating displays occur; indeed, by the time they return to the Arctic, breeding pairs have been established.