White-winged Scoter

The three species of scoters in New Hampshire are ecologically quite similar. All breed in boreal lakes from Alaska to eastern Canada and winter on the Atlantic and Pacific coasts. In New Hampshire they are most common along the coast from October through March, with smaller numbers sometimes lingering into May. In April and May they migrate overland to staging areas along the Saint Lawrence River before continuing north. During this time they occasionally stop on larger lakes and ponds, although usually under adverse weather conditions. After breeding, scoters, like most ducks, undertake a “molt migration.” Adults depart nesting areas for locations where they molt and regrow their flight feathers, thus rendering them flightless for several weeks. For scoters wintering in New Hampshire these molting sites are probably in Hudson and James’ Bays and the Gulf of Saint Lawrence.

When they’ve regained the ability to fly, scoters head back to the coast, again passing overland in a single flight. But as in the spring, they sometimes are forced down onto New Hampshire’s Lakes and Ponds, and this phenomenon is more common in fall. Scoter “fallouts” typically occur if there is rain overnight, although there is much variability in conditions. Black Scoter is by far the most likely species to appear in numbers, and lucky observers might find flocks of dozens – if not hundreds – scattered among several nearby lakes. They invariably appear as a tight clump of ducks in the center of the lake. Surf and White-winged Scoters may be part of these fall-outs, but never in large numbers, and they tend to stay apart from the Black Scoters. Black Scoter is also the more gregarious species in the winter. During this time they are most likely to be found in large flocks, while the other two species are scattered along the coast.

Scoters feed on clams, crustaceans, and (in the summer) insect larvae obtained by diving. The main source of propulsion for these dives are their feet, but sometimes they will partially open their wings to act as rudders, or even flap them underwater a little bit. Available data indicate that scoter populations are declining, although there is much variation and it is difficult to tease apart the three species. Threats are also not well-understood but include climate change, contaminants, incidental capture in fishing nets, and changes to nearshore habitats and prey populations.