Article for November - December 2010
For Wildlife Watchers: Hooded Merganser
by Rob Simbeck
photograph by Phillip Jones
Some people go on and on about warblers. I've been birding for a lot of years, but I've never really caught the warbler bug. Yes, they can be gorgeous, but for my money there's something almost effete about them. They’re small and sort of ornamental, they’re generally hidden in the tree canopy, and it would probably take two years in graduate school for me to begin sorting out their songs and field marks.
Ducks, on the other hand, are working-class, Joe Six-Pack kinds of birds. They're generally right out there in the open, they’re fifty times bigger than warblers (which makes sorting out field marks a lot easier), and vocally, "quack," and the variants thereof, pretty much tell the tale. To top it off, there are a lot of great-looking ducks out there. Harlequin and wood ducks are supermodel gorgeous, and cinnamon teal or ruddy ducks wouldn’t look bad waddling down a runway in Gay Paree either.
And then there is the hooded merganser, one of the more striking assemblages of DNA on the planet. It's handsome enough from the neck down, with rusty sides, a white breast and two black stripes in between, but then there’s that incredible head. As the feathers of the "hood" raise and lower, showing off that cottony circle surrounded by jet black, it looks like a kernel of chocolate-edged popcorn exploding and contracting in slow motion. The yellow eye punctuating the black face and neck helps complete the picture.
Hooded Merganser - Lophodytes cucullatus,"Crested, hooded diver"
Description: Length, 18 inches, with a 24- inch wingspan. Breeding Male is black above, white below, white crest spot, rusty sides. Female is duller brown.
Range and Habitat: Much of the U.S. and Canada. Breeds in swamps, streams, lakes. Winters on the East and Gulf coasts..
Reproduction: Pair bonds form and breeding begins in winter. Lays 8 to 13 eggs, with 11 average, in cavities or nest boxes.
Viewing Tips: In fall and winter, along rivers, estuaries, swamps. Donnelly and Bear Island Waterfowl Management Areas and the Santee Coastal Reserve are all good areas to spot hooded mergansers..
We're talking about the male in breeding plumage, of course. Females tend to be more drab (they don't want to call attention to themselves while sitting on their nests), with a reddish crest, grayish-brown head, and a black-and-white belly.
A small diving bird about eighteen inches long with a two-foot wingspan that weighs in at just a pound and a quarter, the hooded merganser looks like a tricked-out bufflehead. It’s often found in conjunction with wood ducks, since both nest in tree cavities or nest boxes near shallow water. It's an occasional nester in South Carolina, although its primary breeding grounds are farther north, especially around the Great Lakes.
"They seem to be fairly abundant here in winter," says Dean Harrigal, the program coordinator for the S.C. Department of Natural Resources' Waterfowl program. "They can be found from beaver ponds to open marshes, just about everywhere in the state where there’s good wintering waterfowl habitat."
They form pair bonds on the wintering grounds, and the male is in breeding plumage by Christmas, taking full advantage of that spectacular head during courtship displays, throwing it back sharply and bringing it forward slowly while emitting a frog-like croak. The male will also flap his wings and stretch, and the female may bob her head in response. Nests in South Carolina are initiated on average by late February, but nearly always between January 18 and March 22, according to a study by Robert A. Kennamer, a researcher with the University of Georgia's Savannah River Ecology Laboratory in Aiken.
The male is out of the picture by the time the female starts incubating. She will find a tree cavity or nest box and simply rearrange whatever material is already in it, plucking feathers from her breast as the eggs are laid to help keep them warm. A female will generally lay eight to thirteen (eleven is average) white, two-inch eggs, one every other day. Kennamer reported nest predation by animals including raccoons, rat snakes and red-headed woodpeckers. Raccoons and minks also prey on adults.
"Both wood ducks and hooded mergansers will lay eggs in each other’s nests," says Kennamer, "and multiple female hooded mergansers will lay in the same nest." Since they have similar incubation times, at about a month, mixed broods are sometimes hatched and raised together, and there are even rare hybrids.
The young hatch with their eyes open, covered with down, which keeps them warm and makes them buoyant. They are called from the nest by the mother, plunging to the ground and following her to water, where they forage for insects, larvae, snails and tadpoles. Mothers are wary and will keep them out of sight in thick cover, and the young respond to predators by freezing in place or diving. The female will often feign a wound to attempt to draw a predator away. The young fly at about seventy days, not long after the mother has left them to their own devices.
Adults primarily eat fish, and their anything but duck-like bills are a key to their success. Thin and serrated, with a hooked nail on the end, the bills are designed to hold on to otherwise slippery fish. Agile swimmers and divers, mergansers paddle with their heads underwater and dive after fish they spot. It helps that they have a third, transparent eyelid. Besides fish, adults will also eat crayfish, frogs, small crabs, clams and insects. Muscular gizzards help them grind down any shellfish they ingest.
They are awkward on land — their legs are set very far aft — but are one of the swiftest of the waterfowl in flight, with distinctive whistling sounds coming from their wings. Landing, they will skid to a stop on water.
Hunting and logging helped reduce hooded merganser numbers dramatically a century ago, but in recent decades they have benefitted from wood duck boxes erected by conservation-minded citizens. They generally don’t breed until their second year (males get their distinctive plumage in their third), their productivity rate is relatively low, and they are slow to colonize new areas.
With survival a game of inches, it doesn't hurt that hooded mergansers don't taste great. Their fish diets — many ducks eat grains and grasses — give them an oily, fishy taste many humans don't prize, which means hunters don't take as many as they otherwise might.
"They're not a targeted species," says Harrigal. "Most of the time when they're taken by duck hunters they're mistakes or they were shot to be mounted. You can mistake it for a green-winged teal or a blue-winged teal or a wood duck in low light."
He too is a fan of their looks.
"They're darn pretty," he says. "A drake hooded merganser in February rivals everybody when he's got his head in display. Just because he doesn't taste good doesn't mean he's ugly."
And, if you're a wildlife watcher, pretty is much more accessible when it's big.
Rob Simbeck is an award-winning freelance writer living in Nashville, Tennessee.
© 2010 South Carolina Wildlife Magazine, November - December 2010 - www.scwildlife.com