Shoals of Shorebirds
Posted June 2010
As we first glimpsed the familiar, exposed mudflats through a break in the trees, for a moment we were confused. The normally dark brown, pungent, low-tide flats appeared oddly and inexplicably salmon red. Something seemed amiss.
But as the distance closed, we soon realized that the flats, along with the adjacent shallow water, were colored red with the colors of bright shorebirds in stunning breeding plumage.
There were not hundreds, but thousands. Maybe ten thousand shorebirds – Dunlin, Sanderling, Short-billed Dowitchers, and Ruddy Turnstones – huddled together. Some were feeding, many were preening, but most slept, resting up for the long journey soon to come.
May and early June is the time to revel in shoals of migratory shorebirds, the birds that make some of the most dramatic migrations of any animal on our planet.
There are many birds of the shore, but true shorebirds – as scientists and birders call sandpipers, plovers, and curlew – are some of our most heralded and welcome visitors. Only a few species of shorebirds breed near Cape May – just Willet, American Oystercatcher, Piping Plover, Killdeer, and American Woodcock (and rarely Spotted Sandpiper).
Most species of shorebirds are highly migratory. Many new birders and naturalists are astounded to learn that Sanderling – the common “peeps” or small sandpipers that race ahead of the incoming waves and chase after the receding ripples on Cape May beaches – do not breed here.
They may be with us most of the year – indeed ten and a half months – but in the six weeks when they are absent, they journey to the far high arctic tundra to breed and raise their broods. They leave us the last few days of May. By mid-July the first have returned to scurry along Cape May’s beaches. Their journey is one of the many wonders of nature, but one of the most amazing.
There are few better places than southern New Jersey to enjoy migratory shorebirds. Hundreds of thousands grace coastal marshes and mudflats and Delaware Bay beaches. Dunlin, Short-billed Dowitcher, Sanderling, Ruddy Turnstone, and Semipalmated Sandpiper are the most abundant, but 25 shorebird species might be found in a day during the month of May.
As is the norm at Cape May, rarities have also arrived. This spring, a (Eurasian) Bar-tailed Godwit, a stunning male in brick-red plumage, visited Forsythe National Wildlife Refuge. A Curlew Sandpiper (also Eurasian) stopped by Heislerville Wildlife Management Area, two Black-necked Stilts were spotted at the Cape May Migratory Bird Refuge, a Marbled Godwit near Two-Mile, and Wilson’s Phalaropes have been seen in several spots. The low tide beaches on Cape May Harbor, opposite the Nature Center of Cape May, often hold a good variety of bright spring shorebirds.
The Delaware Bay beaches of Cape May County may be the epicenter of spring shorebirding. From the North Cape May beaches and flats north to Reeds Beach and beyond through neighboring Cumberland County, hundreds of thousands of spring shorebirds concentrate to feed on the eggs of Horseshoe Crabs. In this timeless connection of birds and bay, the abundance of Horseshoe Crab eggs fuels the birds for their long journey to the high arctic tundra breeding grounds.
The Red Knot is the poster bird of this amazing gathering, which has been called the second highest concentration of shorebirds in the western hemisphere. Red Knots may double in weight during the two weeks they spend on our beaches, gaining fat reserves that will power their subsequent nonstop flight to northern Nunavut. On their southbound return flight, just a few weeks later, few stop at Cape May. Most head directly to their winter quarters near Tierra Del Fuego, at the southern tip of South America.
A color-banded Red Knot sighted in Florida in 2004 had been banded in southern Brazil in 1984. Banded as an adult, it was at least twenty-one years old in 2004 and had covered almost 400,000 migration miles in its lifetime. By its thirteenth birthday, this 4.5-ounce bird had migrated a distance equal to the moon and back.
To call this amazing, or even a miracle, seems an understatement.
The shorebird spectacle is fleeting and ephemeral.
If you miss it, don’t despair. By mid-July, many shorebirds have returned, stopping off again on their southbound return flight. The colors are mostly muted then, more brown and tan than red as they return to winter plumage. But one similarity remains. In an encore, the mudflats will once more be covered as shoals of shorebirds again bring sound and motion to Cape May’s shining tides.