Summer Reading 2015: Horseshoes Aren’t So Lucky When Dinnertime Arrives

NJ Spotlight | August 27, 2015 | 2015 Summer Reading
Feeding grounds at Delaware Bay and Cape May are crucial migration points for endangered red knot

summer 2015 cramer
While we’re on summer hiatus, we want to make sure we’re still giving our readers something to think about, so NJ Spotlight is continuing its annual summer reading series. Each day we’ll feature an excerpt from a recent book — from nonfiction to novels to poetry — in which New Jersey plays a significant part.

Deborah Cramer’s “The Narrow Edge: A Tiny Bird, An Ancient Crab and an Epic Journey” is a true story of the red knot shorebird’s amazing migration every year from the southern tip of South America to the Arctic Circle — with a critical fuel stop along the beaches of Cape May to refresh on horseshoe crab eggs. But it is a precarious natural balance, one only made more difficult by man.

Cramer, a Massachusetts-based author, traveled the migratory route herself, chronicling at each point this natural marvel, from the tiny shorebird to the ancient story of Delaware Bay’s horseshoe crabs — and talking with the people who are trying to save them both. Here is the start of Chapter Four, her book’s description of Cramer’s first visit to Cape May.

The boat scrapes against the beach. Masses of spawning horseshoe crabs pile up along the waterline. Thick crowds of shorebirds scurry along the sand, grabbing loose crab eggs. The day is overcast and rainy. Neither man nor bird nor crab seems to care. The men unload beach chairs and spotting scopes: Nigel Clark from the British Trust for Ornithology, who after so many springs on this bay now considers Delaware a second home; Richard du Feu, network engineer from the University of Lancaster, who comes from the freshwater of England’s Lake District; and Bram Verheijen, a researcher from the Netherlands. We set up the chairs, adjust the scopes, and begin searching for flagged birds. There are plenty. In Bahía Lomas or San Antonio Oeste, shorebirds would have abruptly taken flight if we’d arrived this noisily. Here, the beach seethes with birds. Intent on eating, they rush across the sand, oblivious to us.
Horseshoe crabs plow through the wet sand like armored tanks. It’s hardly an orderly invasion. Desperate to spawn, they clamber over each other, climb my Wellies, and wedge themselves beneath my tripod, their barnacle-laden shells clicking against each other. Some are the size of dinner plates. Bahía Lomas was empty, quiet, and peaceful. Here, the birds are making a din. The congestion is like Grand Central Terminal at rush hour. A peregrine swoops. En masse the birds rise. The raptor dives at a knot. The knot panics, flying into du Feu’s scope. The peregrine leaves; the flock resettles.

We’re on Back Beach, a thin spit of sand in Mispillion Harbor, Delaware. Shorebirds, exhausted and famished after the long flight from South America, arrive in Delaware Bay, one of the nation’s largest and least-known estuaries. Ignored by millions of people flocking to Delaware’s ocean beaches and the Jersey shore, Delaware Bay, poor sister to better-known Chesapeake Bay, has long held one of the country’s best-kept secrets. For a few weeks every year, as human crowds head to the sea, this bay’s beaches are awash in swarming horseshoe crabs and ravenous shorebirds — the world’s largest concentration of spawning horseshoe crabs and the largest and most important stopover for shorebirds on the eastern seaboard of the United States. For years, so it seemed, only the locals knew.

For most of the year, the large, ungainly, fossil-like crabs live offshore in the deeper waters of the continental shelf, but each spring, on the rising tides of May’s new and full moons, they come ashore. In exquisite and mysterious synchrony, birds and crabs arrive together: crabs to spawn, birds to feast on horseshoe crab eggs. Timing is key. To reach their Arctic nesting grounds and successfully breed, knots double their weight during their two-week stay here. Easily digested horseshoe crab eggs offer fast, energy-rich food to fuel this leg of their journey. In 1986, ornithologist J. P. Myers described the sight as “sex and gluttony on Delaware Bay.” The description fits. Horseshoe crabs, eggs, and shorebirds blanket Back Beach, packed in so tightly the seething mass conceals the sand. The wide reach of Bahía Lomas and the San Antonio port beaches call for a patient, painstakingly slow approach to birds. Here we simply wait as thousands race helter-skelter across the sand, flags coming into view and then vanishing, a sea of knot legs suddenly obscured by smaller, semipalmated sandpipers. The researchers jot down flag numbers, rapidly filling waterproof notebooks. In England’s Wash estuary, du Feu scans for knots in distant mudflats. Here he vacations, simply sitting amid the commotion, where we don’t even need binoculars to take in the fine breeding plumage of dunlin, each with a striking black patch on its belly, or the distinctive feeding style of dowitchers, whose beaks work the sand like sewing machine needles moving along a piece of fabric — all only a few feet away.

The busy birds probe the sand or peck at loose eggs at the surface. It’s raining, it’s windy, and we’re wet, but it’s warm, and even though we’ve been here for six or seven hours, we can’t bear to leave. The tide is ebbing, but the birds haven’t departed. Clark, sustained by his enthusiasm, has eaten only a handful of M&Ms and almonds all day. Mesmerized by the scene unfolding before me, I haven’t noticed time rushing by either. Kevin Kalosz, who runs the Delaware shorebird program, calls a few times, gently urging us to return. The sun is setting and guests are coming for dinner. Clark won’t — can’t — pull himself away. So many birds, so many flags. He estimates that on this tiny piece of beach, we’re sitting in the midst of 4,000 red knots, 5,000 ruddy turnstones, 5,000 dowitchers, 5,000 semipalmated sandpipers, and 15,000 dunlin — a shorebird mecca.

Knots from South America have flown as many as 7,500 miles to reach this beach, working their way up the coast from Tierra del Fuego and San Antonio Oeste. Some stop in the lagoons of southern Brazil’s Lagoa de Peixe National Park, or the sandy mudflats and mangroves of Maranhão in northern Brazil. One knot, Y0Y, flew across the Amazon rain forest from the Uruguay-Brazil border to Ocracoke, North Carolina, a 5,000-mile nonstop flight in six days. Another, 1VL, left northern Brazil on a 4,000¬mile nonstop flight over the Atlantic, arriving in Delaware Bay six days later. No wonder the birds are hungry.

Cape May, a birding hot spot, has attracted outstanding naturalists and birders since the nineteenth century, including the Smithsonian’s Spencer Fullerton Baird and Roger Tory Peterson, yet the wider ornithological community didn’t “discover” the massive feeding frenzy in the bay until 1977, when Jim Seibert, a local decoy carver, and his wife, Joan, called naturalist Pete Dunne, who’d just begun working at New Jersey Audubon’s new Cape May Observatory.

As Dunne recounts in “Bayshore Summer,” his portrait of the rhythms of life in Delaware Bay, the Seiberts told him “the beach in front of their house was awash in birds.” Dunne, who has gone on to write many books and essays about birds and birding, found the beach covered with horseshoe crabs and semipalmated sandpipers, sanderlings, ruddy turnstones, and knots — more knots, he writes, “than were estimated to be in all of North America.” He hadn’t seen anything yet. In May of 1981 and 1982, Dunne, Clay Sutton (whose “Birds and Birding at Cape May,” authored with his wife, Pat, led me to birding beaches, marshes, and trails I would have missed otherwise), Wade Wander, (an expert in counting birds), and renowned ornithologist David Sibley (whose field guide, along with several others, I carried everywhere I traveled in North America) made an aerial survey of this avian Serengeti. Once aloft, these seasoned, experienced birders, like Morrison and Ross in South America, couldn’t believe what they were seeing.

Dunne, who writes that he is “no stranger to numbers of birds” and who has seen flocks of swallows blocking the sun and snow geese rising “like storm clouds,” was dumbfounded to find 420,000 shorebirds, 95,000 of them red knots, blanketing the beaches—just a portion of the shorebirds migrating through the bay each spring. That estimate came in at 150,000 knots out of 1,500,000 shorebirds, making Delaware Bay one of the nation’s most important spring stopovers for migrating shorebirds. In eastern North America, writes J. P. Myers, who did his early research on sanderlings, “no other spot comes close.” In a country where much of the landscape is known or at least traversed, we missed the very heart of this migration. Why?

Buy the book here or here.