WESTCHESTER COUNTY, N.Y. Migrating birds have no way to hide from the kinds of storms we have seen recently the ones that knock out power lines and make human transportation treacherous. They have defenses but are at risk of being blown thousands of miles off course.
Birds that travel over land have the best choices. They can hunker down in a tree or other suitable habitat and wait out a storm or take their chances riding the wind. A rufous hummingbird, a hardy flyer that should be migrating down the Pacific Coast, was spotted recently on the Connecticut coast storm-driven 2,000 miles in the wrong direction. It must find its way back to its proper winter home in Mexico.
Even more amazing is the survival of birds that migrate long distances over open water. For example, take the red knot, a shorebird weighing in at 172 grams. It spends two weeks bulking up with calorie-intensive shellfish on the shores of southeastern Canada and then heads directly out over the open Atlantic Ocean. If all goes well, it will fly 3,700 miles nonstop to its first stopover point, the shores of Brazil a trip that normally takes four to five days. But it flies in the peak of the hurricane season. It often has to navigate multiple tropical storm fronts in its way.
Scientists are gathering fascinating information on how that happens by attaching satellite-tracking devices to larger shorebirds, such as whimbrels. This fall, one whimbrel left Canada for Brazil only to hit a hurricane in the Caribbean. It flew directly into the storm, dropping down to 15 mph. Then it turned east, coming within 700 miles of the Cape Verde islands closer to Africa than the Americas. There, it found the tailwind of the storm and was shot straight back to the coast of Guyana at an average speed of 90 mph.
Scientific advances are just now making it possible for us to fully understand the incredible evolutionary process that allows birds to fly for days without food or water, as well as the navigational expertise that helps them stay on track, returning to exactly the same places each year.
Unfortunately, many of these shorebird species are threatened and in danger of extinction not from storms or other natural hazards, but from human actions. Were overharvesting their food sources, such as horseshoe crabs, and overdeveloping key beach habitat that they depend upon as they migrate.
It would be a shame if, after fewer than 300 years of interaction, we cause the extinction of species such as the whimbrel and red knot. Over centuries, they have learned to adapt to all hazards in their annual 14,000-mile migratory round trip except one: human beings.