Thursday, October 20, 2011

Black Ducks -- © Dave Spier

Black Duck preening at Nick's Lake, Old Forge (autumn) -- © Dave Spier
Frank Morehouse III* sighted two Black Ducks in addition to Wood Ducks, Mallards, Ringnecks, three Hooded Mergansers, one Common Merg, an Osprey and a Great Blue Heron when he was at his camp on Lake Abanakee the first weekend of October. He also heard a Pileated in the mixed woods nearby.

American Black Ducks (Anas rubripes) have been a declining species since the 1950’s. For a time it was thought that hybridization with encroaching Mallards was the cause, but there’s little evidence to support this. More likely, a combination of factors including degradation of their primary winter habitat in the Chesapeake region is the cause. A new study by Ducks Unlimited will look at competition for nesting space, hybridization, depletion of food supplies, winter habitat and other variables.

The Black Duck’s summer range covers much of eastern Canada and New England with a year-round range from the Great Lakes to the mid-Atlantic. The highest breeding densities are in Maine and Nova Scotia according to Ducks Unlimited. Many Blacks migrate further south to a zone from Arkansas to the Carolina’s with higher concentrations to the east.

Blacks are large ducks, the same size as Mallards with the same shallow-water "dabbling" behavior to find food, primarily plants and small aquatic animals.   Some natural foods can be dangerous, though.  Northern Woodlands magazine has an article on a Black Duck that died from eating too many newts.

In bright sunlight at close range, Blacks are actually dark-brown with a lighter brown head. Females and males are nearly identical, although females are slightly smaller and have a greenish bill instead of yellow. In flight the white underwing linings contrast with the dark body. The Black Duck's speculum, the colored patch on the wing, is purple while the Mallard's is blue with two white edges. Also, Mallards have a white tail edge.

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*Frank is from North Creek in the Town of Johnsburg. He attended Ranger School in Wanakena and worked for D.E.C.’s Camp Colby near Saranac Lake. He is now a naturalist dividing his time between the Montezuma Audubon Center and Seneca Meadows Environmental Education Center. His grandfather was a well-known conservation officer in the Adirondacks.

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