Hooded Merganser

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Common Name: Hooded Merganser
Scientific Name: Lophodytes cucullatus

Size: 17.7-19.3 inches (40-49 cm); Wingspan: 23.6-26 inches (60-66 cm)

Habitat: North America; breed in forested wetlands throughout the eastern half of North America and the Pacific Northwest, and may also nest in treeless wetlands where people have put up nest boxes. They are most common in forests around the Great Lakes. Their habitat ranges from spruce-fir forest in the Northwest to pine-hardwood forest and cottonwood-elder riparian forest in the Midwest, to oak-cypress-tupelo forest in the Southeast. Families of newly hatched ducklings forage in shallow water such as marshes, small lakes, ponds, beaver wetlands, swamps, and forested rivers—and rest on exposed rocks, logs, or sandbars. They winter in these habitats as well as on shallow freshwater and brackish bays, estuaries, and tidal creeks, where they often concentrate along the edge of ice. During migration they stop in a wider range of habitats, including open waters of rivers and lakes, brackish coastal bays, tidal creeks, and seasonally flooded forest.

Status: Least Concern. Global population: Unknown amount of adult individuals. The population trend appears to be increasing. Threats include the loss of nest sites as logger’s clear-cut forests, and as agricultural fields replace parklands in North America. Putting up nest boxes in appropriate habitat can help. Diet: Small fish, aquatic insects, crustaceans (especially crayfish), amphibians, vegetation, and mollusks. They dive in clear, shallow forest ponds, rivers, and streams and locate prey by sight. They propel themselves with their feet and use their slender bills to grasp their prey. Ducklings can dive for food right after leaving the nest, at one day old, though their dives are short and shallow during their first week. They also feed by swimming with just their heads underwater. Nesting: Adult males are black above, with a white breast and rich chestnut flanks. The black head has a large white patch that varies in size when the crest is raised or lowered, but is always prominent.

Females and immatures are gray and brown, with warm tawny-cinnamon tones on the head.

Mergansers are tree nesters, using natural tree cavities made from broken limbs or reusing nests created by Woodpeckers. The female makes a shallow bowl nest with materials already present in the cavity, gradually adding down from her belly after she starts laying eggs.

Mergansers often lay their eggs in other females’ nests. This is called “brood parasitism” and is similar to the practice of Brown-headed Cowbirds, except that the ducks only lay eggs in nests of their own species. Female Hooded Mergansers can lay up to about 13 eggs in a clutch, but nests have been found with up to 44 eggs in them.

Hooded Merganser ducklings leave their nest cavity within 24 hours of hatching. First, their mother checks the area around the nest and calls to the nestlings from ground level. From inside the nest, the ducklings scramble up to the entrance hole and then flutter to the ground, which may be 50 feet or more below them. In some cases they have to walk half a mile or more with their mother to the nearest body of water.

Cool Facts: Hooded Mergansers find their prey underwater by sight. They can actually change the refractive properties of their eyes to improve their underwater vision. In addition, they have an extra eyelid, called a “nictitating membrane,” which is transparent and helps protect the eye during swimming, like a pair of goggles.  

Found in Songbird Remix Waterfowl Volume II: Diving and Sea Ducks

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