Blue-Winged Teal

By Joe Kosack, Pennsylvania Game Commission

Every spring, as automatically as March follows February, North America's wintering waterfowl head north to breed and nest in a spectacular migration of short duration that many people miss because they're still spending most of their free time indoors, according to the Game Commission.

"It's really an exciting time, if you're into wildlife and like looking for species that you'll often only see as they pass through on migration," explained John Dunn, Game Commission biologist. "Waterfowl species are easier to see than migrating songbirds that flit through the forest canopy or birds of prey that fly a half-mile above you. Migrating waterfowl are found resting or foraging in areas where there's open water and limited disturbances. Such places aren't hard to find in early spring because fewer people are outdoors.

"Try starting at locations that offer remoteness and wetland diversity or places with plenty of open water; the larger the body of water the better. Roughly two dozen species of waterfowl come through during spring migration and they're always popping into and out of rest areas that meet their varied nutritional needs, offer seclusion, and provide safety through either vegetative cover or sprawling areas of big water."

As they pass through Pennsylvania, waterfowl use the Atlantic Flyway, one of four migratory corridors that ducks, geese and swans follow in North America. All migrations - north in spring, south in fall - correspond with changing seasons and the availability of open water. Birds head north to nest and south to winter in open water.

After spring migrants funnel through the Chesapeake Bay and Delaware Bay on the Atlantic Flyway, their routes branch out across Pennsylvania's breadth and up through New Jersey along the coast in an ever-widening pattern. Those individualized migratory highways take them by historic stopovers that have long provided food and refuge, and, ultimately, to the body of water or waterway where they were hatched and grew up. They typically use the same route, year after year.

"Pennsylvania is a pretty important stopover between the Chesapeake Bay and the Great Lakes for migrating waterfowl," Dunn explained. "Although we don't have a destination as magnetic as a Chesapeake Bay, the state does offer more than 50,000 miles of waterways, two glaciated wetland regions, and a substantial number of big lakes, impoundments and marshes for waterfowl to capitalize on during their migration north.

"Also important to migrating waterfowl are the agricultural lands that surround the state's diverse water resources. Pennsylvania's more than seven million farmland acres provide waste grain, winter wheat and other forage to the wild ducks, geese and swans that wing it north in the Atlantic Flyway."

Migrating waterfowl are birds of a feather in many ways, but they're also very different. Their migration routes almost always target large bodies of water, and most head north at the same general time. But their food preferences vary, as do their tolerances for cold weather and the speeds at which they travel, which range from 40 to 60 mph. Interestingly, no two species follow the same entire migration route, but the sum of their individual routes is defined as the Atlantic Flyway.

Some waterfowl prefer more cover than others, or more shallows, or moving water. The overwhelming majority is looking for open water, because ice impedes feeding and increases threats of predation. Of course, that means just about every wet-spot in the Commonwealth has some waterfowl appeal. And, at least to some degree, it does.

Important migratory stopovers in Pennsylvania include major rivers, like the Susquehanna and Allegheny; intensively-managed impoundments, such as the Game Commission's Middle Creek and Pymatuning Wildlife Management Areas; and, of course, nature's own Presque Isle State Park.

Other great places to check out include Glendale Lake on Price Gallitzin State Park in Cambria County; the Glades on State Game Land (SGL) 95 in Butler County; Raystown Lake in Huntingdon County; Wildwood Lake near Harrisburg; Lake Ontelaunee and Blue Marsh Lake in Berks County; Conneaut Marsh on SGL 213 in Crawford County; Rose Valley Lake in Lycoming County; and Shohola Lake on SGL 180 in Pike County.

Other sites to see waterfowl are irrigation ponds, small farm creeks, remnants of the Commonwealth's old canal system, and agricultural fields. Flighty as they often are, waterfowl prefer to be where they won't be bothered. They covet calm and seclusion and abhor any sort of fast movement or motion and loud noises. Any quiet place with water has the potential to attract waterfowl.

Migration movements are set off by changes in photoperiod - the amount of daylight in a given day - and, to a lesser degree, weather conditions, such as a strong warm wind out of the south. Although snow and frozen surface water will often stall or reverse the procession of migration, the urge in waterfowl to go north is triggered by increasing daylight hours. When winter lingers, waterfowl sometimes starts north before the landscape can accommodate its needs. When birds that live on the water can't access it, they inevitably are forced back to the south.

Winter's conclusion is not decided by photoperiod, a groundhog's shadow or calendar progression. It lasts as long as natural forces support it. Weather is erratic by nature and winter's end is no exception. As a result, waterfowl migrations north are seldom as timely as America's holiday schedule, or as sequential as the days of the week. In fact, they rarely go off without disruptions. But we can surely ballpark waterfowl's passage through Pennsylvania - always underway in March - as confidently as we proclaim the start of spring on March 21.

During migration, waterfowl species are believed to use the sun and stars, as well as mountains, rivers and the coast to help guide them. That's why in foggy and rainy weather, waterfowl often ride it out on the water until high pressure clears the air, and the horizon. Immature waterfowl learn migration routes and pit-stops on their first trip south. The repetition of semiannual migrations seems to help maturing birds stay on course.

But there's something more to the guidance system of waterfowl than terrain and celestial references. Some researchers believe it may be related to the wind or the earth's magnetic field. They suspect these other navigational options come into play only after visual referencing is impaired. Of course, there's no way of knowing for sure. At least not yet.

Mallards, black ducks, snow geese and Canada geese are some of the most visible migrants coming through in spring. Wedges of honking Canada geese cross March's sunny skies regularly. Mallards and black ducks, as well as blue- and green-winged teal, ring-necked ducks and scaup also are seen statewide sometimes in larger flocks, but often in small bands or pairs. Shovelers, wigeons, gadwalls and buffleheads are readily present, as are northern pintails and tundra swans.

Common mergansers work the major rivers, such as the Allegheny, Susquehanna, Delaware, and common goldeneyes use the Susquehanna on their journey north in spring. Ruddy and wood ducks stage in the southeastern counties before making a beeline to nesting areas. Pied-billed grebes and oldsquaw can often be seen on the state's larger lakes and wetlands, while red-breasted mergansers prefer the big waters of the state's glaciated northwest.

Northbound red-breasted mergansers are partial to Lake Erie's waters, as are canvasbacks, common loons and redheads. Coots gather in their largest spring numbers at Presque Isle, but also can be see throughout the state.

"March typically provides the best window of opportunity to see the greatest number of species," Dunn said. "Try to get afield when a warm front is pushing through, and wear clothing that will help you blend with your surroundings. Getting out early and late in the day usually provides the best chances to catch incoming and outgoing migrants at local rest-stops, but sneaking around on a sunny afternoon also can be productive, because waterfowl feed throughout the day."

Binoculars and field guides are a big help to those heading out to observe migrating waterfowl and whatever else is on the move. It's always enlightening to identify what you're seeing because then you can determine whether it was something special or a common species. Binoculars will get you closer and a good field guide will provide snapshots of everything you glass.

Visit the Game Commission’s online version of this article for wildlife photos.

Wildlife notes on diving ducks, puddle ducks, wood ducks, mallards and Canada geese are available on the Game Commission website

The agency also offers a bird song audio "identiflyer" through "The Outdoor Shop" on its website.

3/2/2007