A few weeks ago, in early August, we were lucky.

Without having glanced at a tide chart, we happened to stop by Wharton Point in Brunswick just as the tide was receding from its high point. The air was still and clear; there was the familiar smell of marsh grass and mud birders know so well. Across the water, gray-backed common terns turned their reddish bills down toward the surface of the bay as they scanned for schools of tiny fish that might wander close enough to the surface to become a meal.  An osprey beat its way across Maquoit Bay toward the Mere Point peninsula.

All of that would have been enough. It often has been when we’ve stopped by here in the past.

But we were lucky.

A snowy egret, shocking white against the backdrop of gray water, flew up the bay. We watched it through binoculars fly farther and farther away until it landed along the edge of a salt marsh perhaps a half mile in the distance. That’s when we noticed that there more on that distant shore.

That was lucky enough. But it wasn’t the end of our luck.

Just then we heard a plaintive “puwee” from somewhere farther up the bay where it narrowed and eventually became a stream in a salt marsh. It was the sound of a black-belled plover.

Black-bellied plovers are stout, black-legged and black-billed shorebirds. They have black bellies in the spring and summer and pass through coastal Maine in May on their way to their breeding grounds far to the North in Arctic Canada. As summer begins to fade into fall, they begin making their way south again, their black bellies disappearing as they molt into the more modest gray back and white belly for the winter months.

We pulled the telescope out of the back and scanned as a mudflat began emerging with the receding tide.

There they were—a flock of at least eighty black-bellied plovers. Had they just flown down from the Arctic, leaving behind scenes of polar bears stalking the tundra to grace us with their presence on a salty mudflat on the coast of Maine?

We continued scanning, and there were more shorebirds. Lesser yellowlegs and greater yellowlegs dancing about on their long, bright yellow, stilt-like legs. Tiny semipalmated sandpipers and even tinier least sandpipers rapidly searched the flats for food. A few short-billed dowitchers, probed their very long bills (despite the name) into the muck. A single garish ruddy turnstone, rufous and black with yellow legs, busily scampered around. Like the black-bellied plover, it is also an Arctic Canada breeder making its way south for winter.

As the tide receded, the birds moved closer, following the edge of the water in search of small crustaceans to fuel their long journey south. Some of these birds will go as far south as South America; others, to the Caribbean and Central America, and some to the southern U.S. and Mexico.

We felt connected in that moment to something bigger than ourselves: to the cycles of life on planet earth that brought us together with creatures that had just left the faraway cold of the Arctic and that would be soon be clinging to the muddy roots of mangroves in the steamy hot tropics.

We were lucky.

Jeffrey V. Wells, Ph.D., is a Fellow of the Cornell Lab of Ornithology and Vice President of Boreal Conservation for National Audubon. Dr. Wells is one of the nation's leading bird experts and conservation biologists. He is a coauthor of the seminal “Birds of Maine” book 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 working statewide to protect the nature of Maine. Both are widely published natural history writers and are the authors of the popular books, “Maine’s Favorite Birds” (Tilbury House) and “Birds of Aruba, Bonaire, and Curaçao: A Site and Field Guide,” (Cornell University Press).