This Week’s Creature Feature

Migrating to their winter home, tundra swans will soon be filling the gap in the sky left by south-migrating osprey. Our snowbirds could be arriving any day.

Most of their 3,000-mile journey south from their homes in Alaska and Canada occurs during November, according to Larry Hindman, the Water Fowl Project Leader of the Maryland Department of Natural Resources.

The birds migrate in family groups. Parents with their young plus teens and non-breeders all fly in the famous V form that most migratory birds write in the sky.

“They migrate because it’s their ancestral genetic makeup to move south to the coast to escape severe winter weather,” Hindeman explains. “They can’t forage when the lakes are frozen. They have to move south of the freeze line and snow cover.”

To keep their strength and weight up, the swans break for food and rest, taking to the air again recharged and able to fly nonstop another 1,000 miles.

Weighing between 13 and 20 pounds — with females slightly smaller than males — tundra swans need every inch of their seven-foot wingspan to stay aloft. When they catch a good air current, these powerful appendages allow them to reach speeds of 100 miles per hour.

The sound of their beating wings explains why tundras are also known as whistling swans. This, as well as their high, melodious woo-hooing call can be heard all along their journey.

Most of the 90,000 traveling birds winter in North Carolina. But many stop in Maryland. Last January’s count found 18,000 wintering in Maryland. They settle on the the Susquehanna flats, the Eastern Bay, the Chester River and the Potomac River as well as tributaries along both shores.

In Chesapeake Country, Hindman says, the big birds “spend most of their time on the Bay feeding on five species of clams and Bay grasses.” The swans are dabblers, meaning they turn tail and feet up to graze on shallow bottoms. 

“Some have developed the behavior to feed on waste grain, like fields of barley,” Hindman says.

The spring thaw — mid-March to early-April — signals their departure. So Chesapeake County and the Atlantic Coast are vacated by tundra swans just about the time osprey return.