Common Merganser

1/5000s at f8.0, ISO:800, Canon Mark III 1Ds w/800mm

The Common Merganser is a large duck, of rivers and lakes of forested areas of Europe, northern and central Asia, and North America. It eats fish and nests in tree cavities. Like other mergansers, these fish-feeding ducks have serrated edges to their bills to help them grip their prey; they are therefore often known as "sawbills". In addition to fish, they take a wide range of other aquatic prey, such as molluscs, crustaceans, worms, insect larvae, and amphibians. Since a tree cavity is needed for nesting, it requires a mature forest as its breeding habitat; they also readily use large nesting boxes where provided, requiring an entrance hole of 6 inches in diameter. The female lays 617 (most often 812) white to yellowish eggs, and raises one brood in a season. The ducklings are taken by their mother to rivers or lakes immediately after hatching, where they feed on freshwater invertebrates and small fish fry, fledging when 6070 days old. The young are sexually mature at two years old. In winter they may move further south where ice-free conditions exist on lakes and rivers.
Esters Park, CO