One of the greatest wonders associated with birding is the astonishing feat that is long-distance migration. Most birders at some point are likely to ask themselves how a bird born in New England in the spring or summer knows how and where to migrate to its wintering grounds and then find its way back the following year, a pattern to be repeated year after year. It is as if I get set with Alvin and embark on a trip from my house in Arlington, Massachusetts, to my winter haven in Costa Rica, all without ever having traveled that route and without asking a single person (or consulting a GPS device) for any help or direction along the way. Imagine us trying to use the sun, the stars, the earth’s magnetic field, and other landmarks or information to complete our journey.
It is well worth pausing to contemplate the migratory abilities of the birds we see through our binoculars or scopes every spring and fall. As you receive this issue of Bird Observer, the fall migration has already started, primarily composed of shorebirds moving through New England. When you look at a Red Knot through your scope, think of the fact that it is one of the longest-distance migrants of any bird species, traveling about 9,300 miles from its Arctic breeding grounds to the Tierra del Fuego archipelago off the southernmost tip of South America. Better understanding of migratory routes for all birds, including the Red Knot, has led to enhanced conservation efforts to preserve critical stopover sites for the birds, such as those used by Red Knot and other shorebirds in the Delaware Bay region.
But what really strikes at my heart is seeing a bird that has returned to the same spot at our Vermont home, indicating that it had made it to its wintering grounds, survived the winter, and overcame all obstacles to get back to our mutual home. For every disheartening story of birds killed during their migrations from man-made obstacles, such as tall buildings, wind turbines, or high tension wires, there are the heart-warming stories of individuals successfully navigating across the hemispheres despite natural and man-made dangers.
Even though I can listen to lectures or read about how and why birds migrate, it still sends shivers up my spine to think about what long-distance migrants are able to do. I vividly remember a passage in Scott Weidensaul’s superb book, Living on the Wind: Across the Hemisphere with Migratory Birds, where he describes setting up a scope on his deck in Pennsylvania on a clear autumn night with a full moon. He set the scope sights directly on the moon, and over the next hour counted the birds he saw passing across the light of the moon. He then used his count to estimate how many birds migrated over his area during that one hour based on what he saw in the tiny sphere of the moon in the sky, and came up with an approximate count of 8,340 birds. The scene evokes awe, wonderment, amazement, and deep appreciation for these migratory feats and the sheer number of birds involved.
It is not just the distance the birds travel, be it 46,000 miles covered in annual migrations by the Arctic Tern or mere miles by short-distance migrants. It is how they do it, most notably as a first-year bird setting off for a place it does not know, perhaps relatively nearby or perhaps thousands of miles away. This is one of the most impressive phenomena in the animal kingdom. Those of us in New England know that birds setting off from the East Coast in late August and September over the Atlantic Ocean toward South America may well encounter tropical storms or hurricanes during their journey. Tracking data on Whimbrels revealed that the birds are even able to fly—at a clip of 31 miles an hour—through the heart of massive oceanic storms to get to their destinations.
Recognition of the importance of all segments of a bird’s annual cycle has led to a relatively new field in ornithology, migratory connectivity. Weidensaul, in a 2012 article (http://www.audubon.org/magazine/march-april-2012/unlocking-migrations-secrets), noted that ornithological research for centuries had focused primarily on the bird’s breeding grounds. The study of migratory connectivity links individuals and populations throughout their annual cycle. Data from all locations that a bird navigates throughout the year enables more focused and effective conservation efforts to stem declines in bird populations. Weidensaul discussed the example of the American Redstart, where the quality of its wintering habitat in Jamaica (the wetter and buggier the mangrove swamp, the better) was the primary predictor of its breeding success in North America. Thus, conservation efforts on the summer breeding grounds of the American Redstart would be to little avail if declining winter habitats in Jamaica were not addressed.
To me, one of the most amazing migrants is the Blackpoll Warbler. I cannot imagine this tiny bird flying non-stop for three days over the Atlantic Ocean before landing in South America. It is difficult enough for our Blackpoll Warblers in New England, but even more astonishing is that Blackpoll Warblers that breed in Alaska fly clear across the North American continent to the East Coast to join their eastern counterparts before heading down to South America.
I am truly humbled by the epic flights of long-distance migratory birds. This is one reason that I so often say, when listening to a returning migrant, “Welcome back, and good luck, little fellow!” These birds deserve our respect and appreciation beyond our simple pleasure of seeing their beauty and reveling in their song. Their migratory wanderings evoke strong emotions for me and help sustain my connection to each and every bird that I hear. That is a wonderful thing and a pillar of my passion for birding.
Martha Steele, a former editor of Bird Observer, has been progressively losing vision due to retinitis pigmentosa and is legally blind. Thanks to a cochlear implant, she is now learning to identify birds from their songs and calls. Martha lives with her husband, Bob Stymeist, in Arlington. Martha can be reached at email@example.com.