On our last afternoon at Longboat Key, a large flock of red-breasted mergansers moved south on the calm waters of Sarasota Bay. Demonstrating military discipline, they moved in unison, heads directed forward. Numbering 150 or more, not a bird fluttered or peeped as they passed our vantage point. The adult males, uniformed in their crisp, sharp-edged colors, occupied the flanks of the brigade, clearly the captains of this militia; the females and immature mergansers, dressed in dull-brown fatigues, dutifully followed their direction. The silent flock eventually moved beyond the edge of a mangrove island and the avian parade was over.
Red-breasted mergansers summer and breed across northern Canada, Alaska and Greenland. Often migrating in large flocks, they winter on coastal bays of North America, as far south as Mexico. Tolerant of salt water, they are far more common on brackish bays than are common or hooded mergansers. Like their cousins, they dive from the surface to catch fish and other aquatic creatures with their long, serrated bills.
