Decades ago, we witnessed for the first time the incredible spectacle of thousands of shorebirds—mostly red knots and sanderlings—in a constantly moving mass along the thin ribbon of sand on a southern New Jersey beach. They were there to feed on the eggs of horseshoe crabs. The large brown pear-shaped female crabs, looking a bit like misshapen army helmets, slowly and silently made their way through the shallow water and onto the beach amid the deafening chorus of the thousands of laughing gulls that were also there to feed on the horseshoe crab eggs.

It was an experience that we will never forget.

But is it an experience that will only be a memory?

That question is artfully, thoroughly, and engagingly explored in a new book by Deborah Cramer published by Yale University Press called “The Narrow Edge – A Tiny Bird, An Ancient Crab & An Epic Journey.” Cramer has constructed the book around her own journey following the migratory route of the red knot, in this case the most endangered of the red knot populations—those that pass through the Atlantic Coast of North America (including Maine) in migration. She starts in the desolate windswept shores of Tierra del Fuego in southernmost South America where the birds winter and recounts the tales of the first researchers who discovered a previously unknown concentration of red knots there in 1979 by driving a beat-up rental car thousands of miles and checking every beach they could get close to. It’s details like this that make Cramer’s story compelling, and her vivid descriptions of the areas she visits gives a sense of what it felt like to be there. Describing waiting to meet some research scientists on the exceedingly windy, cold beaches of southern Chile she writes, “My eyes tear in the wind. I’m squinting to shut out the sting.” It’s easy to imagine, and we know that feeling well.

From South America, Cramer travels north to the most famous of the migratory stop-over locations for red knots, Delaware Bay. Throughout the book she effortlessly weaves in history, whether it’s the origin of the bird’s name, what early naturalists knew about red knots and horseshoe crabs, or the history of the way people have used, and continue to use, the coastal beaches and tidal estuaries where the birds feed. The chapters about the human use of horseshoe crabs, including now by the medical industry that uses their blood, offer some of the best understanding of the issues that have led to major decreases in the numbers of horseshoe crabs that come ashore to lay eggs.

From here Cramer flies north to the Arctic where she must learn to handle flares and a gun in case a polar bear gets too close as she joins a research team looking for the incredibly hard to find nests of red knots. Her stories of the early ornithologists’ race to find the first red knot nest and eggs are particularly interesting.

The next stop south for many of the red knots coming from the breeding grounds is another remote and little known area, the shores of James Bay. Here, scientists, over the last decade or so, have found major concentrations of red knots and other shorebirds using the extensive and remote estuaries and mudflats to fatten up before heading farther south on their way to South America.

For anyone interested in birds and bird conservation but who wants to read about it through the human interest stories of a writer and the researchers the author meets, we heartily recommend “The Narrow Edge – A Tiny Bird, An Ancient Crab & An Epic Journey.”

Jeffrey V. Wells, Ph.D., is a Fellow of the Cornell Lab of Ornithology. Dr. Wells is one of the nation's leading bird experts and conservation biologists and author of the Birder’s Conservation Handbook. His grandfather, the late John Chase, was a columnist for the Boothbay Register for many years. Allison Childs Wells, formerly of the Cornell Lab of Ornithology, is a senior director at the Natural Resources Council of Maine, a nonprofit membership organization. Both are widely published natural history writers and are the authors of the book, Maine’s Favorite Birds.