Saturday, May 18, 2013 · 10:00 a.m.

Riverwalk Bird of the Week: Hooded merganser

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Hooded mergansers are small ducks with a thin bill and a fan-shaped, collapsible crest that makes the head look oversized and oblong. (Photo: Charles Dean)

The folks in the Riverwalk Bird Club don't just watch birds. The group includes some excellent photographers.

Nooga.com Outdoors is happy to share their great photos by featuring a Bird of the Week.

This week, we feature hooded mergansers (male and female), taken by Charles Dean.

Interesting facts
“Hooded” is something of an understatement for this extravagantly crested little duck. Adult males are a sight to behold, with sharp black and white patterns set off by chestnut flanks. Females get their own distinctive elegance from their cinnamon crest. Hooded mergansers are fairly common on small ponds and rivers, where they dive for fish, crayfish and other food, seizing it in their thin, serrated bills. They nest in tree cavities; the ducklings depart with a bold leap to the forest floor when only a day old.

—Along with wood ducks and other cavity-nesting ducks, hooded 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 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.

—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 little fluffballs 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.

—On the bird family tree, hooded mergansers (Lophodytes) lie between goldeneyes (Bucephala) and the other North American mergansers (Mergus). They share many courtship behaviors and calls with both of those groups.

—The hooded merganser is the second-smallest of the six living species of mergansers (only the smew of Eurasia is smaller) and is the only one restricted to North America.

—The oldest hooded merganser on record was 14 years, 6 months old.

This information is courtesy of the Cornell Lab of Ornithology. 

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