A flock of tundra swans is an impressive sight

Last week as I traveled across the southern tier of New York, V-shaped skeins of Canada geese crossed the sky from north to south.

It was a vintage November day — cold, gray and damp.

At a rest stop near Jamestown, another flock caught my eye. But these birds were bigger and pure white.

Tundra swans

What a treat to see a flock of tundra swans.

November is the best time to encounter these impressive birds as they head to wintering grounds on the Chesapeake Bay.

In flight or at rest on a lake or river, swans make a lasting impression.

Swans are huge, all white birds, seemingly impossible to misidentify, but clueless hunters sometimes mistake them for much smaller snow geese, which are easily recognize by their black wing tips.

Tundra swans measure about 52 inches long with a 66-inch wing span and weigh about 15 pounds.

Mute and trumpeter swans are much larger — five-feet-long with a wing span of about 6 1/2 feet and weighing about 23 pounds.

Mute swans

Mute swans, which are not mute, are the common swans of country estates, city parks, and zoos.

These exotic birds easily escape confinement and establish feral populations. The bright orange bill with a fleshy black knob at the base is distinctive, and at rest, mute swans hold their long necks in a graceful S-curve.

When a mated pair faces each other, their heads and necks seem to form a heart.

Tundra swans, the species you’re likely to see this month in migration, is all white with a black bill. Many, but not all, adults have a yellow spot at the base of the bill.

At rest, a tundra swan’s neck is more erect than a mute’s. And often a tundra swan’s neck is stained a rust color from iron-containing minerals encountered while grubbing for submerged aquatic plants.

Trumpeter swans

Trumpeter swans are the largest native waterfowl in North America. Though much bigger than tundra swans, trumpeters are visually almost identical, except trumpeters never have a yellow spot on the bill.

Like tundras, trumpeters also often have rusty stained necks. In fact, every trumpeter I’ve ever seen has had a rusty neck.

In flight, both tundra and trumpeter swans hold their long necks straight and outstretched. Even at a distance, their necks appear as long as their bodies.

Trumpeter swans are the least common of the three species found in North America.

Survey

According to the U.S. Fish & Wildlife Service, the most recent range-wide survey of trumpeters occurred in 2000, and counted nearly 24,000 birds.

In the first year of the survey (1968), biologists counted only about 4,000 birds.

In the early 1900s, only about 70 birds were known to exist in and around Yellowstone National Park.

The advent of aerial surveys helped biologists locate many more swans, particularly in remote areas of western Canada and Alaska.

Trumpeter swans have never been listed as endangered in the U.S., thanks in part to reintroduction efforts in many states, including Ohio and Michigan.

Both states, where trumpeters were once extinct, now have small breeding populations. Swans mate for life.

Nest

If muskrats are present in a marsh, swans often built their nest on top of a muskrat house. Absent muskrats, swans gather submerged aquatic vegetation until the nest reaches a diameter of six to 12 feet and about 18 inches high.

In building the nest, swans pluck vegetation from around the perimeter of the nest, resulting in a circle of open water around the nest.

Swans typically lay four or five eggs, and incubation takes about 35 days.

After the eggs hatch, cygnets (young), cobs (males) and pens (female) form tight family groups.

During the first few weeks of life, cygnets eat a high protein diet of aquatic invertebrates.

By two months of age, cygnets switch to an adult diet of leaves, stems and tubers of aquatic vegetation.

In feeding experiments with captive adult swans, they eat as much as 20 pounds of aquatic vegetation each day.

Cygnets grow rapidly. In just 10 weeks, they grow from hatching weight to near adult-size, and they can fly when 10 (tundra) to 14 (trumpeter) weeks old.