SPRING BALLET

North Iowa’s March weather has been typically unstable. But there are some undeniable signs that spring is in the air. And perhaps nowhere is the impending change of seasons more dramatically obvious than in the skies above our natural wetlands.

Following months of ice and snow, area ponds and marshes are beginning to thaw; some wetlands are completely open. For millions of wild ducks, the signals are irrefutable; the wintering grounds of the Sunny South have lost their allure. Gripped by a sudden restlessness, migratory waterfowl feel the irresistible urge to move. The time has come to head north.

Surging across the North American continent on centuries old pathways etched deep into their DNA, the birds collectively embark on an urgent race toward the nesting grounds of their ancestors. During the next couple of weeks, more than twenty species of waterfowl will pass through Iowa. Although many of the birds formed pair bonds during the winter, others have not. By the time the migration reaches the upper mid-west, competition becomes keen as a surplus of bachelor males aggressively compete for an increasingly limited number of available hens. As the rivalries gain momentum, human observers are presented with an opportunity to witness one of the greatest spring shows on earth.

Wild birds employ many strategies for attracting mates. Songbirds sing. Spring gobblers fan their tails and strut their stuff. By contrast, wild ducks take to the air where single hens lead bands of drakes on a merry high speed chase through the warming skies. Compact flocks of mallards, pintails, teal, and others twist and turn above the thawing landscape. After speeding across marshlands on low level maneuvers that nearly brush the cattails, the hen will suddenly rocket skyward taking the drakes with her. Then, with a sudden change of mind, the hen will turn to plummet back to earth. With a sound like tearing canvas, the drakes turn in unison to follow her coarse. Courtship flights may last, nonstop, for a half hour or more. The intensity of the flight never wanes as each drake pulls all the stops to prove to the female that he’s the very best choice. Spring courtship is serious business and it may take the hen several days and several hundred miles to make her decision. But in the end, she will finally choose — picking the drake who is clearly superior to all the rest.