Migration forces

In a masterfully crafted piece on nationalgeographic.com, David Quammen traces the paths and explores the reasons for animal migration. Animal migration is distinct from other animal movements since, as biologist Hugh Dingle explains, they are prolonged, linear, and focused movements that carry animals beyond their familiar habitats. Quammen further explains: "Migrating animals maintain a fervid attentiveness to the greater mission, which keeps them undistracted by temptations and undeterred by challenges that would turn other animals aside." When people build roads, houses, and other bottlenecks that force migratory animals from their singular journey, survival is threatened.

Two weeks after I landed in France to start my first post-college job with a conservation organization, I was lathering on mosquito repellent and untangling migrating barn swallows from mist nets. From late August through early October, hundreds of thousands of barn swallows roost in Provencal marshland while on their way to the Sahara. By day the swallows disperse to feed, but around sunset, the birds come back to the flooded reedbed to roost. I had never before worked with birds so closely (I'm a plant girl!), but I had to learn quickly on the job, as each evening at least 10,000 swallows swoop onto an acre of reeds for the night. A Rocha France, my employer, is working with local farmers to encourage them to leave flooded reedbeds and marshlands of the Rhone River untouched. While some farmers hesitate to let valuable land lie, all who come to the roost site during migration season are shocked and awed into agreement: migration is a mighty force to be reckoned with.

Quammen's article communicates such images with conviction. It reads like a novel and you may be impressed, as I was, as the author literally walks in the trail of migration. Quammen concludes the article with an image of 60,000 sandhill cranes rising from a marshland after a rest on their journey. "It was the accrued wisdom and resoluteness of evolution that I was witnessing, airborne above the Platte. If we humans have accrued equal wisdom and can summon equal resoluteness, I thought, maybe we'll allow them to continue their journeying a while longer."