Shorebirds: Wonderful Waders
May 9, 2012
Filed under Feature Stories
Summer is when many of us head for the water, and that likely means beaches and big lakes with large stretches of shoreline and the likelihood of spending time in the presence of any number and variety of shorebirds. Shorebirds are the waders of the avian world, birds that do not swim like ducks and geese, but are still closely associated with water. Shorebirds feed in the shallows or moist areas at the edges of wetlands, often probing the water for small insects and crustaceans.
From a biological standpoint, the term “shorebird” technically refers to birds belonging to the order, Charadriiformes, which includes plovers, sandpipers, oystercatchers, gulls, stilts and other similar species — the birds you commonly see along coastal beaches and marshes. They are also abundant on shallow inland lakes and wetlands.
Shorebirds are fascinating to birders for a variety of reasons. Some of these birds are strikingly beautiful. The American avocet, a wading bird with slender bluish legs, bold black and white markings on the body and golden-buff plumage on the head and neck is considered by some birders to be the beauty queen of American birds.
Other shorebirds have unique or specialized adaptations that set them apart. Long-billed curlews nest in wetlands and grasslands in the northwestern and north-central United States and southern Canada, migrating to southern coastal areas in the winter. They have exceptionally long, downward-curving bills. The bill of a curlew may exceed 8 inches in length, making it the longest bill of any shorebird in North America; and relative to its size, the curlew has one of the longest bills of any bird in the United States. Curlews use this lengthy probe as a tool for catching insects in tall grass.
Shorebirds also intrigue birders as an identification challenge. While novice birders easily identify many of these birds, distinguishing between certain types of sandpipers and gulls can tax the skill of even the most astute ornithologists. Coupled with the delight of an identification challenge, the travels of these birds are also intriguing. Western sandpipers that measure a mere 6 inches from their bill to tail tips make an incredible migration. These small sandpipers nest on the far reaches of North America on the northern coast of Alaska. In the fall they migrate to the southern coastlines of the Atlantic and Pacific Oceans in places such as Florida, Texas and California. Other shorebirds push the migration envelope even further. Lesser golden-plovers nest on the barren lands of the high arctic and may winter as far south as southern South America, traveling across two continents on their annual migrations.
Habitat monitors are interested in shorebirds for other reasons. Because they often feed on aquatic organisms and insects, environmental disasters such as oil spills or pollution discharge can quickly affect local shorebird populations. Shorebirds can be impacted by habitat or population problems with their food sources. For example, in 2003 horseshoe crabs experienced a dramatic decline in spawning in Delaware Bay. This prompted red knots, a small shorebird, to alter their migration patterns. Disruptions to normal shorebird activity or declines in the population of certain species may indicate local, regional or even global conditions that negatively affect their habitat.
From killdeers to black-necked stilts, yellowlegs to sandpipers, shorebirds are fascinating to observe and identify. They’re found nearly everywhere you travel in the United States. The more we know about shorebirds, the better we can understand and care for their world, and ours.