In Search of Tundra Swans A-Swimming
Friday, December 15, 2006
If you live near the Chesapeake Bay or are just plain lucky, you may have seen one of our winter jewels flying in lately.
Thousands of snowy-white tundra swans migrate every year from the far north to the warmer waters of the bay and its many tributaries. As they fly, their wings often make a whistling sound, so they used to be called whistling swans. The earliest swans may arrive in November, but the bulk of them probably arrived with last week's cold front, said Larry Hindman, waterfowl project manager for the Maryland Department of Natural Resources.
"The swans will take advantage of prevailing northwest winds," Hindman said.
Can you blame them? When the swans arrive, they will have flown anywhere from 3,500 to 4,200 miles from their tundra homes on the north slope of Alaska and the Arctic National Wildlife Refuge and on the eastern side of the Hudson Bay. Even without wind at their back, they can fly more than 50 mph at an average altitude of 2,000 to 4,500 feet. They make the trip in stages, spending time in the Dakotas or Wisconsin or around Lake Ontario before freezing temperatures drive them farther south to feed on underwater grasses and mollusks near the bay. With wingspans of more than six feet, they are majestic to behold aloft and atop the water. Or so I'm told.
My first attempt to see tundra swans at Caledon Natural Area, east of Fredericksburg, Va., came up empty. Caledon, named in 1659 by its first settler after the impressive Caledonia forest of Scotland, is a favored spot for some tundra swans to weather the cold. Between 200 and 800 tundra swans have historically taken winter residence at a secluded pond near the Potomac River. The pond is usually off-limits to protect the birds, but Caledon offers escorted tundra swan tours during the season, including one Saturday at 9 a.m. for ages 13 and older.
The tour begins in the visitors center with a brief history of the 2,579-acre site, which was donated to the state by the Smoot family in 1974 because the area is an important habitat for bald eagles. Visitors pile into a van that takes a winding tour through Caledon's second-growth forest. (I had arranged for a weekday tour with Sammy Zambon, the chief ranger, so we took his smaller truck.) On the way, we drove slowly and had our eyes peeled for redheaded woodpeckers, which frequent this stretch of woods. We passed several of the park's six hiking trails, including the 3.5-mile Boyd's Hole Trail, which circles through an American bald eagle habitat. (This trail is closed during breeding season, April through September.) We were also on the lookout for a resident flock of turkeys but sighted two Cooper's hawks instead.
When we came to an open area with a stand of dead trees called Alder Flats, Zambon stopped the truck. This section of the park had been flooded to create a better bird habitat. As if on cue, a mature bald eagle perched atop one of the dead trees. It remained motionless while we trained our binoculars on its regal profile. When it suddenly took flight, Zambon pointed out an incoming pair of mature eagles and a younger eagle nearby. (Immature eagles have brown bodies and heads.) Four eagles at once! Not bad, I thought.
When we reached the Potomac River, Zambon parked the truck on a sandy beach, and we hiked through the underbrush toward the end of Jones Pond, where the swans are normally spotted. While the river was brown and buffeted by the high winds, the pond looked smooth and blue, protected by a slim stretch of beach and golden grasses. The pond offers an ideal spot for the swans: 52 acres of protected water that is only three feet deep on average. I could just imagine how lovely a large white swan would look descending on the shining waters, but our eyes scoured the skies in vain. We saw only a group of mallards on the pond. Last year, a group of swans arrived earlier than this but didn't stay the whole winter because the temperatures were so warm, Zambon said.
"Birds have wings, and they are where you find them," he said, quoting a friend. As my luck would have it, a group of 26 tundra swans arrived at Caledon two days after my departure.
Caledon is one of many sites across the area where you might find swans. Tundra swans can be identified by their black bill, which often has a yellow spot at the base, and by their black feet. They also have a long, slender neck that they hold straight in the air while swimming. They are not to be confused with mute swans, a nonnative species that was originally raised in captivity. Mute swans are larger than tundra swans and have a curved neck and an orangy knobbed beak. Mute swans are reputed to be aggressive toward other birds and are contributing to the decline in underwater vegetation in the bay area.
Unfortunately, the number of tundra swans that winter with us has been decreasing over recent decades. Most experts think this is because of increased pollution in the bay and the decline of underwater grasses. Many of the swans have headed farther south, especially to North Carolina, where they glean leftovers from farm fields.
The tundra swans will stay with us until the thaws of late February and March, when they begin their long trek back north to breed. They become airborne by running across the top of the water and slapping their huge wings on its surface before they lift off.