February 3, 2012
North Carolina

Fewer swans wintering at North Carolina refuges

By: Phil Dickinson | Winston-Salem Journal, www2.journalnow.com 3 February 2012

Picture a fallow cornfield or shallow lake this time of year. Now picture them covered with large, white birds moving about as they feed. Or maybe they are just sleeping peacefully on the water. Each year, thousands of tundra swans migrate to winter refuges in eastern North Carolina. I just returned from a birding trip to the Outer Banks. The swans were a sight to behold.

Tundra, or whistling, swans are large, almost 5 feet from head to tail, have a 5½-foot wingspan and weigh more than 20 pounds. They breed on the Canadian tundra, thus their name, but in winter they seek unfrozen habitat along both coasts of the United States. Two places they like are Lake Mattamuskeet National Wildlife Refuge and Pocosin Lakes National Wildlife Refuge near Columbia.

Swan numbers are down this year at the two sites with only 2,000 or 3,000 at each. These totals remain impressive to see, even when compared with an estimated 20,000 at Pocosin’s Pungo Lake unit three years ago. The reasons for the decline are not known. Are they staying farther north in a warm winter? Is there less food? Along Maryland’s Eastern Shore, feral populations of the tundra’s cousin, the mute swan, are also blamed, but more on that later.

At their winter residences, tundra swans sleep on the water, but they often move to nearby agricultural fields to feed during the day. The Mattamuskeet and Pocosin locations provide the ideal combination of food and water.

The movements of wintering swans and snow geese would have jeopardized birds and pilots had the U.S. Navy’s plans for a nearby airfield come to fruition. Now, the birds face another danger: a proposal to install wind-energy turbines near Pocosin. Creatures that fly are not easy to relocate.

Swans migrate in large flocks, but on breeding grounds far to our north, the mating adults spread out and only young birds or nonbreeding adults group together. Courting pairs put on quite a display, flapping their wings and making lots of noise as they face each other. Males help with incubation and care for the young. Parents will fight off small predators, but in the event of a wolf or bear, they try to hide the nest by quickly leaving the area.

If you have seen a swan on a pond at a park or resort, it probably was a mute swan with its gracefully curving neck and an orange bill bordered by black. Adult tundra swans have black bills. Mute swans were introduced into the United States about 100 years ago. Over the years, many have escaped and bred in the wild. Not only are they not native, but they are considered invasive. A number of states are taking steps to control their populations.

Around Chesapeake Bay, their numbers have increased significantly. They eat underwater bay grasses, and one bird can consume 8 pounds of grass a day, tearing up the root or rhizome in the process. Tundra swans and many ducks also depend on the bay grasses for food.

In Maryland, the numbers of wintering tundra swans reportedly have plummeted by 40 percent in the past five years, and mute swans could be a factor. That state now has a management plan for mute swans after a 2004 law removed them from protection as migratory birds. North Carolina has yet to experience this problem, but wild mute swans sometimes are seen in small numbers at Pea Island on the Outer Banks and in a few other places.

By the way, mute swans can make noise. They merely speak more softly than other swans.

Christmas Bird Count. On Dec. 31, 53 people in 11 teams fanned out across Forsyth County as a part of the 112th edition of this national event. Local birders tallied 82 species and 7,442 birds that day, with seven more species reported during count week beginning three days earlier. Starlings were the most common bird, closely followed by ring-billed gulls. Bald eagles and great egrets showed up for the Forsyth count for the first time. Baltimore orioles, cackling geese and blue-winged teals also were nice surprises.

URL to article:  https://www.wind-watch.org/news/2012/02/03/fewer-swans-wintering-at-north-carolina-refuges/