The Plight of the Red Knot: How One of the Most Endangered Migratory Birds Is Shoring Up against Its Imperilled Global Flyways
Baker, Allan J., ROM Magazine
One of the most magnificent sights in the world takes place at the far ends of the earth, in places like Tierra del Fuego, northwest Australia, New Zealand, and South Africa: huge flocks of shorebirds circle high in the sky, calling excitedly as they begin their arduous journey to breeding grounds in the arctic tundras of the northern hemisphere. No matter how many times I witness it, the sight fills me with awe. And no wonder: some of these migrating birds travel 30,000 kilometres annually back and forth between their northern breeding sites and the southern feeding grounds where they spend the winter.
To fuel their remarkable journeys, the birds need suitable feeding sites along their flyway, or route. I like to use the analogy of a 747 aircraft taking onboard large amounts of fuel before departure for a world-wide flight, stopping at a few widely spaced refuelling sites. Unfortunately for these birds, only a few good refuelling sites--wetlands with abundant food supplies--exist around the world. Many of these critically important wetlands face destruction or degradation, threatening many shorebird species with huge population declines and eventual extinction. In 2003, global surveys of 207 shorebird populations showed that about half were declining in number, while only 16 percent were increasing. This ranks shorebirds as the most endangered group among all species of migratory birds in the world.
My own concern for migrant shorebirds began in 1995, when my great friend and colleague, Professor Theunis Piersma of the Netherlands, inspired me with his cutting-edge ecological research on red knots. This shorebird species, a bird slightly larger than an American robin, is the ultimate long-distance migrant. Six different subspecies of red knots migrate along global flyways from southern wintering sites to discrete breeding grounds in the high Arctic tundras. To my chagrin, I realized that the rufa subspecies of red knot that flies through Ontario--my own backyard--had one of the smallest populations of all.
Thankfully, Brian Harrington from the Manomet Bird Observatory in Massachusetts had been conducting pioneering work, laying the foundation for understanding the flyway of this subspecies. He had discovered that these birds, which winter in Tierra del Fuego, have the longest flyway of all the knot shorebirds. They migrate north and refuel in Argentina and Brazil at key wetlands, then make a huge flight into North America, where they refuel for the final leg to the Arctic.
That same year I decided it was high time to roll up my sleeves to better understand this amazing flyway--and to get involved in applied conservation work. Rather than pressing on with my usual taxonomic work in the office and lab, I needed to head out to the field and capture and band birds so we could estimate--and try to contribute to--their survival in different parts of the flyway.
When I challenged Theunis to come along, he agreed, and became part of an international team that joined me in February 1995 in a ROM-led expedition to Tierra del Fuego, the southern terminus of the red knot flyway. Our objective was to determine how many knots were present near the town of Rio Grande, where we know these birds live when it is winter in the northern hemisphere. We aimed to catch and band a good sample, so that we could begin the task of estimating the annual survival rate of adults by recapturing them in subsequent years. On that expedition local people from Argentina joined us, including Luis Benegas from the Museo De La Ciudad Virginia Choquintol in Rio Grande and Patricia Gonzalez from Fundacion Inalafquen in the northern Patagonia town of San Antonio Oeste, about 1,400 km north of Tierra del Fuego.
Little did I know then that San Antonio Oeste held the most important wetland in Argentina. Red knots depend heavily on it to refuel during the northward migration to the Arctic. …