Fowl family tree has unique twist

Swans: The mating of a common mute and a rare trumpling creates a new species.

October 23, 2001|By Laura Vozzella | Laura Vozzella,SUN STAFF

WARRENTON, Va. - Dr. William Sladen has explored Antarctica, studied waterfowl in Siberia and taught Canada geese to fly behind an ultralight plane. The five young swans splashing on the edge of a pond here are his latest adventure.

To the untrained eye, the birds waddling around central Virginia's Airlie Center look like the common mute swan, which is considered a pest in some parts and even a threat to the environment, hardly an object of intrigue for a famous wildlife researcher.

But Sladen stands on the edge of the pond, rapt.

"I can't make out what these bills are," he said one recent morning, peering at the mottled pink-white-and-gray triangles jutting out of the bird's heads. "Those bills look so straight."

The five swans are a cross between the common mute and the rare trumpling swan. It's an unprecedented combination, a new species created on the shores of Columbia's Lake Elkhorn in the spring when natural attraction overtook scientific planning.

Sladen and other scientists are taking a keen interest in the five "mutling" swans that hatched in an incubator at the 3,000-acre Airlie Center preserve after their mother was shot in Columbia in April. They're watching closely for hints of what they'll look like and how they'll behave as adults.

Swan experts are eager to see whether the birds will resemble their mute father or their trumpling mother, or whether they'll look like a combination of the two. There is more here than the simple curiosity of new parents looking into a bassinet for echoes of great-grandma's eyelashes or dad's chin.

It is a battle between the good guys and bad guys of the swan world, between the underdog trumplings and the overly abundant, destructive mutes. Scientists are openly rooting for trumpling traits but conceding that the mute genes seem to be winning out.

Regardless of how the birds turn out, scientists are relishing the chance to watch the cygnets grow into mature swans, to see the first few pieces of the mutling puzzle snap into place.

"They are starting to open the curtain on the show," said Brooke Pennypacker, an ultralight pilot who lives at Airlie Center and has helped raise the cygnets. "Everything is going to be kind of a surprise."

The five birds are half mute, a nonmigratory species that hails from Asia but popped up in the Chesapeake Bay region in 1962 after a few escaped from an Eastern Shore estate where they'd been kept as pets. Now the area is overrun with about 4,000 of them, threatening native birds and the bay with their aggressive behavior and voracious appetite for underwater grasses.

The five are also half trumpling, a species that is a mix between the trumpeter and whistling swans, two native American swans capable of migrating between Alaskan tundra and the Gulf of Mexico.

As many as 100,000 trumpeters are thought to have wintered on the East Coast or in the Midwest in Colonial days, but early settlers nearly hunted the birds to extinction for their meat and feathers.

Today, scientists say, fewer than 20,000 exist nationwide.

As part of a program to reintroduce native swan species to the region, Sladen has kept a pair of trumpling swans on each of Columbia's three manmade lakes since the late 1980s. Sladen, 80, was a friend of Columbia's founder, James W. Rouse, and his wife, Patty. He even named a pair of swans after them.

After the feathered Jim died of an infection in February 1996, researchers paired Patty up with a succession of other trumpling males. But in the spring, 19-year-old Patty rebuffed her trumpling mate and took up instead with a mute swan who lived at the lake.

The mute-trumpling match was a first, say scientists, who know that's the case because trumplings live only in captivity.

The pair produced seven fertile eggs, but soon afterward, in late April, Patty was shot in the head with a BB gun. Police arrested a 17-year-old Columbia youth in May, charging him with cruelty to animals and destruction of property. Each misdemeanor charge carries a maximum prison sentence of three years, in addition to fines.

The Sun is not identifying the teen because he is a juvenile. He was scheduled to go to trial last week, but the proceedings were postponed until Dec. 4.

After Patty's body was discovered, Airlie scientists gingerly transported her seven eggs to the preserve. Six hatched, and five cygnets survived.

Since then, the birds have slept in a pen with a baby monitor, its companion monitor tucked by Pennypacker's bed. They've also been coddled and schooled by a human "stepmother" so devoted that she once stripped down to her underwear and jumped into a frigid pond to teach them how to swim.

The birds are weighed every third day. They're photographed - in profile, to monitor bill growth - nearly that often. Researchers take notes daily on the way the swans communicate, hold their necks and pitch their fits, looking for mute or trumpling traits.

The five seem to be a mix, with mute characteristics dominating.

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