knot like quail
When winter gets tough, quail can’t pick up and leave for more hospitable digs. They are permanent residents of this land and live or die depending on the goodwill and stewardship of the people who manage public lands, farms and those who hunt. Unfortunately there’s not much good will because quail populations are crashing. But what about shorebirds, they can fly to the other end of the world to find suitable wintering habitat? But do they really escape the indifference?
Take the red knot. All red knots breed in the the Arctic, but some fly to Tierra del Fuego — 10,000 miles away — to winter (actually, the Austral summer) in Patagonian wetlands that look and feel like those they use in the Arctic summer. Others fly only as little as they need to. This year we watched over 2,000 knots semi-winter in Avalon NJ, staying until December before a strong nor’easter pushed them south. The most ambitious of these migrants will fly as far as Brazil and Cuba, while others – birds from the same Avalon flock – will stay just south of harsh winter weather, in Maryland, Virginia, or Cape Hatteras.
Over the last two years I have worked with teams along the Atlantic Coast to attach light-sensitive geolocators to red knots to help understand the diversity of their migration paths, the duration of their stopovers and where they eventually spend the winter. Although there is much to learn from all the data, the long flights are the most intriguing. Flying long distances cannot be taken lightly by people or animals.
To understand, pretend you are taking a flight from the Arctic to Tierra del Fuego, but instead of taking an airliner, you’re flying solo in an ultralight. You’ll have a compass to navigate, as do long distance migrant birds, but like the birds you will have to take long flights over water. These flights can be as long as 6 days non-stop because there isn’t anywhere to land, just uninterrupted Atlantic Ocean. So when you’re looking out at the sea in your feather-light craft, you will be asking the same question as the knots – “when should I leave?”.
Just recently my colleague, Ron Porter — a Cornell trained engineer turned geolocator expert — helped us move closer to answering that question. He used geolocator data, from red knots we trapped in 2009 at Monomoy National Wildlife Refuge and recovered the following year, to create a list of all the flights they took over the one-year life of the geolocator. For most birds there were about 5 to 10 flights of various distances between Monomoy NWR and wintering areas, from wintering areas to Arctic breeding areas, and finally back to Monomoy where the birds were recaptured. Ron approximates the beginning and end of a flight by the geolocator’s log of “wet signals” or times when birds are in salt water. The cessation of a wet signal indicates the beginning of a flight, the start of a wet signal marks the end of the flight; (i.e., birds have landed and have their feet in the water). Ron then linked each flight with weather reports from weatherspark.com, a remarkable site that compiles historic and real time weather from major and minor airports in the US, Canada and South America countries.
So what is the answer to that little question: When do you leave . . . . on a flight that could leave you struggling to save your life in a storm, against winds that are blowing you further out to sea? The answer is complicated, as with most questions dealing with migration ecology. Much of the information you need to answer this question would become very clear if you were to take your ultralite to cross the sea — make sure you have enough fuel, wait for at least one day of settled weather with following winds, and hope you’ll have several more days of following winds to speed your flight and conserve your fuel. Navigation will be key but, even if you carry a compass, your actual coarse will depend on the wind and weather. You could get blown off course and have to fly against winds that deplete your fuel. In the case of a red knot, you might have to slow down from wear or exhaustion; if there is no place to land, you may be done for.
But are knots immune from the same lack of concern that threatens quail? Sadly the answer is no. What can a bird do after a long flight desperate to find land only to be shot dead, (the French shoot migrating shorebirds at important carribean stopovers like Barbados, Quadalupe and French Guiana)? What happens when you finally make shore after a long, exhausting flight from South America and can’t find food because fishermen have decimated horseshoe crabs on Delaware Bay, (whose eggs are are a high-quality resource for shorebirds)? What happens when after a long flight you arrive at your wintering area and find it increasingly overrun by vacationers who care nothing for sharing the beach with birds?
The key for both quail and red knots is the same. People need to care and unfortunately caring people are in short supply.