Thousands of the birds have made their annual trek to the refuge.
By Christian Berg
Of The Morning Call
Bird watchers from across the mid-Atlantic region are flocking to the Pennsylvania Game Commission's Middle Creek Wildlife Management Area, where thousands of tundra swans have gathered to prepare for their spring migration to arctic breeding grounds.
The swans' late-winter arrival at the 5,000-acre refuge in Lancaster and Lebanon counties is a highly anticipated annual event among birding enthusiasts. With as many as 10,000 of the graceful white birds congregating on Middle Creek's main lake at any given time, their presence ranks as one of Pennsylvania's top ornithological attractions.
''We are very, very lucky to have this literally in our backyard, because most place in the United States don't get anywhere near these birds,'' said Donald Heintzelman, a nationally-renowned birding expert from Upper Milford Township. ''It really is a big deal.''
An avid birder and wildlife photographer, Heintzelman is the author of more than 20 books and has been honored by the American Ornithologists Union. Although he has been watching tundra swans in Pennsylvania for more than 50 years, he never tires of them.
In fact, Heintzelman has already made two daytrips to Middle Creek this winter and plans several more visits before the birds head north later this month.
''You've got to admit, they are really spectacular birds,'' he said. ''I don't know why I keep photographing them. I have zillions of photos, but you can always get a better one, I guess. It's just enjoyable.''
THE SWAN STORY
The tundra swan (Cygnus columbianus) is the smallest, most abundant and most widely distributed swan in North America. They are true long-distance migrators, spending as much as five months a year in transit as they crisscross the continent from frozen breeding grounds in Alaska and northern Canada to wintering areas along the Atlantic and Pacific coasts.
There are an estimated 140,000 tundra swans in North America — 60,000 in the West and 80,000 in the East. Most of the eastern population spends the winter around the Chesapeake Bay, Delaware Bay or Pamlico Sound in North Carolina.
John Dunn, a Game Commission waterfowl biologist, said an estimated 25 percent of the continental tundra swan population passes through Southeastern Pennsylvania each year. Most of them concentrate around Middle Creek and along the Susquehanna River, feeding in grain fields by day and resting on the water at night.
''They need a lot of fat reserves [for migration], and what happens here is pretty important,'' Dunn said.
Studies have shown that swans can lose up to 18 percent of their body weight during winter and are at their lowest body weight of the year during the spring migration.
Tundra swans measure four to five feet long and have a wingspan of about five-and-a-half feet. Adults weigh 10-18 pounds, with males slightly larger than females. Both sexes look alike, featuring all white feathers, black legs and black bill. Most adult tundra swans have a yellow spot in front of the eye.
Tundra swans are the only native swan species found in Pennsylvania, but mute swans — which were introduced from Europe — also are commonly seen. Tundra swans are easily distinguished from the much larger mute swans, which have orange bills with black bulbs at its base. Mute swans also hold their long necks in an S-shaped curve, while tundra swans typically hold their necks upright.
While tundra swans are graceful fliers that can reach speeds up to 50 miles per hour, they require a lengthy running start to take off from land or water. They also are excellent swimmers, using their necks to reach up to three feet below the surface for aquatic vegetation, which comprises the bulk of their diet.
Tundra swan pairs mate for life and typically return to the same breeding area each year. They build a ground nest of grass, lichens and moss, with the female laying a clutch of three-five eggs. Young swans, called cygnets, hatch 31-32 days later and can fly at two-three months of age.
Tundra swans are relatively long-lived animals, with the oldest recorded individual reaching 21 years of age.
A LIMITED ENGAGEMENT
Although tundra swans gather at Middle Creek in large numbers, the length of their stay is fairly small. Considering how many thousands of miles the birds must travel each year, they simply don't have the luxury of loafing too long.
The exact timing of the swans' departure varies from year to year, depending on the weather. But it typically occurs around mid-March, and perhaps a bit later if wintry weather persists.