Champions of flight, endurance freaks, evolutionary marvels: The wind birds
For the extreme migrants, including shorebirds, nesting season is over and “fall migration” has begun already in July and August. While our resident species like Carolina Wren are working hard on a third or fourth (and possibly fifth?) brood for the year, shorebirds’ itinerant ways only allow for a short breeding season with a single successful nest (hopefully) before they start the great trek from the Arctic back to South America. Small clutch sizes, a limited breeding window, and epic migrations make for a hard existence. Add habitat changes such as coastal development, sea level rise, and changes in the timing of insect hatches in the arctic due to climatic shifts as well as some hunting pressure and it’s no wonder most shorebird species are declining. They’re some of the greatest migrants on Earth with the ability to see magnetic fields, sleep one side of the brain at a time, change the size of their gut during migratory flights, and fly for thousands of miles without stopping for food or water. And they do it without being able to glide like an albatross or swim like a gull.
We tend naturally to evaluate species in anthropomorphic terms, thinking of birds as rather dumb creatures. After all, shorebirds’ credulous nature is one reason it was so easy to hunt them to near extinction. On the other hand, shorebirds as a group have found the evolutionary bleeding edge of the physiologically possible and have resided there competently for millennia, out-flying Peregrine Falcons, out-distancing the seasons, and circumnavigating hurricanes at sea by methods still invisible to us.
Long-billed Dowitchers during their southward migration in fall. Notice their missing primary feathers, indicating that they are molting flight feathers during this stopover in Mississippi.
Semipalmated Sandpipers resting and preening their feathers during a spring migration stopover in Mississippi.
They do all this with little margin for error. Consider the rite of passage for juvenile shorebirds. Once nestlings have fledged, adult shorebirds leave the nesting grounds to fatten up for southward migration. The juveniles are left to themselves. A few weeks later the juveniles take their own flight southward, long after mom and dad have disappeared into the horizon. Consider a one-month-old embarking on a transcontinental journey, for some species meaning a week or more of nonstop flight over open water. It’s unimaginable. But for shorebirds it is a basic part of survival.
Champions of flight, endurance freaks, evolutionary marvels — they grace the open spaces of Mississippi with their presence briefly enroute twice annually. And when they begin to arrive on the southward journey, a few of us head out into the August heat to pay our respects and take inspiration from those who live at the razors edge with such grace.
