Shorebirds

Joe Meche is a member of the board of directors of the North Cascades Audubon Society and has been the editor of the chapter newsletter for the past six years. Joe has been photographing birds and landscapes for over thirty years and has been watching birds for more than fifty years.

Every spring, one of nature’s most awe-inspiring spectacles takes place (see Whatcom Watch, “Beaks and Bills,” July 2002). Around the world, billions of birds respond to the biological imperative to procreate and travel thousands of miles to do so. Birds migrate northward in spring in numbers that are almost incomprehensible.

Since they are birds of open areas associated with water, shorebirds are often the most visible of migrants. Along the Atlantic and Pacific flyways, spring is heralded more by the migration of shorebirds than by the traditional harbinger, the American robin.

Festivals have been established to celebrate and follow the movements of shorebirds along both coasts as they move northward to their breeding grounds on the relatively safe Artic tundra regions of Canada and Alaska. In some years during the spring migration, the incredible numbers of shorebirds concentrated in certain areas create a natural spectacle that must be seen at least once in a lifetime.

Many shorebirds are long-distance migrants, and some species fly directly from their wintering grounds to their breeding grounds. Other species, however, must stop to refuel along the way. Most of the stops are at estuaries and beaches along their route, where exposed tidal flats provide the necessary fuel.

Shorebirds begin probing for food as soon as their feet hit the ground. Two classic areas for watching shorebirds during spring migration in North America are Delaware Bay, on the East Coast, and Gray’s Harbor on the West Coast.

Most shorebirds, or those known collectively as sandpipers, belong to the family, Scolopacidae, of which there are 43 species in North America. They range in size from the large long-billed curlew to the tiny least sandpiper.

Throughout the range of sizes of shorebirds, there is also an impressive variety of specialization among the species. Some shorebirds have short legs and short bills, while others have long bills and long legs. As you become familiar with shorebirds and observe them as they feed, you will notice how well-suited each species is to its particular niche in the feeding scenario.

Many shorebirds locate prey by touch or smell as they forage in the wet habitats they prefer. Their diet consists primarily of inveterbrates that are gleaned from the water or the ground or by probing in the mud. A foraging flock of dowitchers has been said to resemble a flock of sewing machines, given the frenetic up-and-down motion of their probing bills. Turnstones and surfbirds probe for meals along rocky shorelines.

If you’ve ever been birding or just walking along the beach in the winter in the Northwest, you might have noticed those twisting, shifting clouds of birds flying above the shorelines or tidal flats. They move in a synchronous rhythm, something that resembles the work of an avian choreographer. You watch in awe and wonder how they can do it. How can they avoid colliding with each other? What are those birds? If you’ve observed this spectacle, then what you’ve seen are more than likely flocks of dunlin.

Large flocks of dunlin, which can number in the thousands, forage on the soft sediments of tidal flats and can sometimes be found in flooded fields inland. Dunlin are the only shorebirds that occur in large numbers in Whatcom County during the winter. Keep in mind that whenever you witness the incredible aerobatic display of a flock of dunlin, they are usually trying to evade a hunting falcon, which you can probably locate if you look above or behind the flocks.

The evasive aerial maneuvers utilized by dunlin and other shorebirds have been observed and studied for many years. As birds feed actively along beaches and mud flats, the slightest disturbance can cause the entire flock to take flight. They then turn and twist in swift flight and the mass of birds appears to move as one.

Some observers contend that the flock follows the movement of the lead bird flying out front. Others have noted that the lead bird can sometimes be on the edge of the flock or even in the middle. It appears that this mystery is still far from being solved. If you’ve ever witnessed this phenomenon, you’ve noticed how the contrast of the white underbellies with the darker backs might serve to confuse a predator as the flock wheels and turns.

Other characteristics of shorebirds that aid in evading predators are their long, pointed wings and tapered bodies. Their flight is rapid and they can turn on that proverbial dime.

County records of dunlin numbers over the years have been impressive, to say the least. While flocks of 5,000 to 10,000 are not altogether unusual, one observer, in January of 1993, reported an estimated 50,000 dunlin at Drayton Harbor. Including dunlin, approximately 32 shorebird species have been observed in Whatcom County. Other shorebird species that can be observed in winter, albeit in lesser numbers, are black turnstones, common snipe, and sanderlings.

A subfamily of sandpipers consists of the Wilson’s, red-necked, and red phalaropes. Phalaropes have lobed toes for swimming and these birds spend much of their lives on the water. Phalaropes are a joy to watch when they’re feeding, as they swim in tight circles, jerking their heads back and forth, picking insects off the surface of the water as well as out of the air.

Most shorebird nests consist of a simple scrape on the ground, where the female lays two to four eggs. Shorebird chicks are precocial and are out of the nest and foraging within hours of hatching. Phalarope chicks are capable of swimming an hour after hatching.

At least one shorebird parent remains with the chicks during their first weeks. The speculation of many researchers is that the female often leaves the rearing of the chicks to the male while she fattens up to regain the energy lost during the production of eggs.

It should be noted that other species of birds from other families fit into the overall category of shorebirds. Washington has recorded thirteen species of plovers, one oystercatcher, the black-necked stilt, and the American avocet. In Whatcom County, black-bellied plovers have been recorded on at least twenty Christmas Bird Counts (CBCs); black oystercatchers can be found on rocky shorelines; and killdeer are common, widespread breeders in the county and have been recorded on every CBC.

Make plans to visit areas that are frequented by shorebirds to add a little spice to winter days. The single best place to observe shorebirds in Whatcom County is Marine Park in Blaine. The four covered shelters that overlook the flats are ideal observation sites, even on rainy days.

Other good locations are the extensive tidal flats on the south end of Drayton Harbor, the north end of Birch Bay and Lummi Bay, the vast delta at the mouth of the Nooksack River, Padden Lagoon, and the north end of Chuckanut Bay.

When planning a trip to see shorebirds, optimum viewing will be with the incoming high tide. If you see shorebirds actively feeding out on the tidal flats, stake out a good spot on the beach or on the edge of the flats and wait. The tide will bring them right to you. For best results, take your tripod and a scope. You might want to take along a snack and a good book as well.

Shorebirds are a fascinating group of birds. They are finely-tuned organisms that are extremely well adapted to their environment. They come in a variety of sizes and can be strikingly beautiful in their breeding plumage. They can pose identification challenges, especially when you encounter similar-sized birds in winter plumage, but you will enjoy getting to know them. Their energy enlivens a beach or tidal flat, whether they’re feeding or fleeing. §