by Joe Kosack, Pennsylvania Game Commission

Spring draws closer with each setting sun. Its approach creates a stir in wintering snow goose populations that erupts into migration, sending them north by the tens of thousands to the Game Commission's Middle Creek Wildlife Management Area.

Although their name connotes winter, and the possibility of snow still accompanies most weekly weather forecasts, snow geese soon will be converging on Middle Creek - on the Lebanon/Lancaster county line - in their annual spring migration to their northern nesting grounds. Many other species will be doing the same thing, but they just don't have the compelling presence that thousands upon thousands of bright-white snow geese create while crossing a sunny sky or yakking it up in an agricultural field. Their arrival confirms spring's imminence, although it doesn't assure an end to snow. However, it does provide one comforting thought: there is less to winter than there was.

This winter has been an odd one. Enjoyably - and sometimes even uncomfortably - warmer than Pennsylvanians are accustomed to, winter has been almost anything but, for much of December and January in the state's eastern counties. Some trees and plants had been coaxed into sprouting prematurely for spring. A few bears roused out of winter dens to prowl.

Winter birds are working the fields, instead of birdfeeders. Schools haven't been canceling - hardly even delaying - for snow. Few eastern Pennsylvanians have held - much less used - a snow-shovel since last winter. That mildness compelled some snow geese to head northward. Then winter reclaimed Pennsylvania's portion of the Piedmont and Appalachians. The snow geese didn't stay.

"During an early January warm spell, we had about 15,000 snow geese at Middle Creek and a flock of about 5,000 at Muddy Run in southern Lancaster County," said John Dunn, Game Commission waterfowl biologist. "Then winter rolled back in and the 'early birds' went south. When warmer weather moves in again, the birds will start pushing north.

"If there's a few inches of snow on the ground, or the surface of Middle Creek's main impoundment is frozen, it's a good day to stay home, because when snow geese labor to find food or open water, they generally head south, often back across the Mason-Dixon Line. Despite their name, snow geese really don't seem to have much tolerance for snow and cold weather. On the other hand, tundra swans, another spring migrant that frequents Middle Creek, seem more willing to tough it out and wait for the snow to melt."

Although they sometimes head north prematurely, Dunn said snow geese usually have their migration timing down.

"Their movements north are generally triggered by photoperiod - or the length of daylight in a day - the availability of open water for resting, and snow-free fields for feeding," Dunn said. "Access to open water and food is vital to these birds. Coming north before they have it almost always leads to a southern retreat."

At the height of migration, 100,000 to 150,000 snows may converge on Middle Creek creating a surreal, pulsating panorama that allows observers time to take in and comprehend. So if you're interested in experiencing the biggest show, timing is everything.

To help visitors sort out when to come, the Game Commission regularly posts updates on Middle Creek's snow goose and tundra swan numbers on its website. When migration is on and snow geese are dropping anchor at Middle Creek on their trek north, they usually number in the tens of thousands.

Of course, there's no guarantee snow goose numbers will build to six figures here, or that they'll even stay within viewing distance from the roads that wind through Middle Creek's tapestry of rolling hills, forested areas, croplands and wetland-dominated lowlands. Waterfowl lives intuitively, and its daily movements between sunrise and sunset are largely random; they go where they will. That's why the Game Commission's Middle Creek updates are subject to rapid and dramatic change.

"What is here in the morning may start leaving in the afternoon or the next day," said Jim Binder, Middle Creek's resident manager. "But they also may stay for several days, or even weeks. Bird migrations - triggered by photoperiod - are fluid and strongly influenced by weather conditions, such as a strong southern wind. One thing's for sure, though, they're on the clock after they pull out of their wintering grounds and you can figure that Middle Creek's biggest flocks will have passed through by mid-March."

Periodic updates about Middle Creek's snow goose and tundra swan numbers can be found on the Game Commission's website (www.pgc.state.pa.us) by clicking on the "Watchable Wildlife" link in the right-hand column and then, under the Middle Creek Wildlife Management Area menu, selecting "Waterfowl Migration."

Middle Creek is one of the southernmost staging areas that snow geese use. They typically stay two or more weeks before heading further north. Snows start migrating northward from their wintering grounds in February. But it's not a fast trip back to their nesting grounds in the Canadian arctic.

En route, the large birds hit key staging areas where they rest and eat as heartily as possible to build energy reserves that will fuel their journey - often at an elevation of about 2,000 feet - and greatly influence their reproductive potential upon arrival at their nesting grounds.

When they leave Middle Creek, snow geese head for the St. Lawrence River estuary, their last major staging area before pushing through to the arctic region. The estuary, more than 300 miles long, is one of North America's most important marine ecosystems and an exceptional stopover for migrating snow geese. After this, snow geese will move with purpose toward their nesting grounds. There the birds will scuffle with the elements and arctic foxes to fulfill their migratory mission to nest and raise young.

When they occupy Middle Creek, snow geese often can be observed working the fields for food and resting on the large impoundment. They're usually pretty vocal and aren't necessarily flighty. Wildlife watchers who keep their distance and use spotting scopes or binoculars, generally get quite a show. If something spooks the sprawling accumulation of geese, they take flight, often en masse, in an uplifting event that will please even the most ardent curmudgeon.

In the early 1990s, snow geese came to Middle Creek in relatively limited numbers. Then, in 1997, a phenomenal 150,000 snows blanketed the management area's fields and large impoundment, and the birds have been visiting in large numbers pretty much ever since then.

The Atlantic Flyway population of snow geese currently numbers about one million. The growth in the greater snow goose population has been phenomenal. In the 1930s, there were only a few thousand. Now, the population is twice as large as the goal of 500,000 set by Canadian and United States waterfowl managers.

The tundra swan's occupation of Middle Creek parallels that of snow geese. Traditionally, swans leaving their wintering grounds further south used to stage on the Susquehanna River and, when they were ready, headed north. Now, Middle Creek - along with the Susquehanna River - has become a migratory staging area that is used each spring by several thousand tundra swans.

Since its creation in the 1970s, Middle Creek, which is part of the larger State Game Land 46, has become a critically important migratory bird stopover and staging area. The 6,254-acre property also contains a 400-acre lake and a wide variety of waterfowl-friendly potholes, ponds and wetlands.

"Middle Creek's habitat diversity and intensive management are responsible for making it so appealing to migratory waterfowl," Binder said. "Through its restricted areas, wildlife plantings, habitat enhancements, and wetland creation and manipulation, Middle Creek has been molded into an area that now rivals the Susquehanna River in waterfowl appeal. It has become a waterfowl oasis in a portion of the Atlantic Flyway dominated by intensive farming and development."

Snow geese weigh six to eight pounds and have a four- to five-foot wingspan. Tundra swans weigh 14 to 18 pounds and have a six- to-seven-foot wingspan. Both species feed on waste grain, winter wheat shoots and grasses, and aquatic vegetation.

"Toward sunset, and as long as there's open water, waterfowl converges on the main impoundment," said Binder. "Nightly returns and sunrise liftoffs are about the only snow goose movements we can forecast. When they may arrive, where they go to feed and how long they stay at Middle Creek is strictly up to the birds and closely related to weather conditions."

On weekends, Middle Creek draws a considerable number of spectators who come to see waterfowl. Weekdays are typically much slower paced. There are driving routes to follow with plenty of roadside pull-offs, as well as trails to hike. There also are restricted areas where public access is denied. Pending weather and road conditions, the driving routes may be closed.

"One of the reasons we're able to attract and hold large numbers of waterfowl is because we have large restricted areas that are off limits to human activities," Binder said. "These areas are well-marked and monitored regularly. Individuals who enter these areas will be fined."

Middle Creek's visitor center, which houses a large wildlife exhibit, is a good first-stop for newcomers. This visitor's center is two miles south of Kleinfeltersville, Lebanon County, just off Hopeland Road, near the lake's western shore. It is staffed and open to the public six days a week. Its schedule is: Tuesdays through Saturdays, 8 a.m. to 4 p.m.; and Sundays, noon to 5 p.m. The center is closed on Mondays.

For more information, visit the Middle Creek Wildlife Management Area webpage.

2/9/2007