If I say I’m going to write about potholes, I know some of you will think I am referring to the axle eating black holes found on our highways at this time of year, but you’d be wrong. As you slalom your way down the road, trying to avoid the next crater, think for a moment about the true geologic potholes that are spread across Minnesota, the Dakotas, Nebraska, Iowa and Montana. These special bodies of water support 50% of North America’s migratory waterfowl and more than 60% of the breeding mallards, gadwall, blue winged teal, northern shoveler, northern pintail, redheads and canvasback ducks.
These potholes were created ten thousand years ago as the last glacier melted away, leaving behind uneven ridges of rocks and soil and chunks of ice that slowly melted beneath the glacial debris and left behind the myriad ponds that pock the surface of the land. Potholes generally refer to a body of water smaller than a lake and are usually sustained through snow melt and precipitation.
As the asphalt potholes are expanding on our roadways, the aquatic potholes are just beginning to emerge from their winter cover of ice and snow; just in time for the arrival of millions of waterfowl who have depended on these special wetlands for centuries. You don’t have to be a duck hunter to appreciate the value of these potholes or the beauty of the birds that come through each spring and fall, but conservation groups like Ducks Unlimited that have been leading the charge to preserve and restore the prairie potholes. They know that these places are critical feeding and breeding ground for so many species of ducks, geese and swans. Potholes support different forms of aquatic life and plants not found in larger lakes and they are adapted for these annual migrant visitors. Unfortunately, the shallow lakes have been degraded over the years by extensive drainage systems, if not completely erased from the landscape in our efforts to expand agricultural land. In years with less snowfall, like this year, they are starting out with a deficit.
Potholes not only support migrating waterfowl, they also are home to many other species of bird, mammal and reptile because of vegetation that grows around the edges. As the water warms we begin to hear the wonderful songs of the spring peepers and chorus frogs – sounds that always make me smile inside and out. It is a true sound of spring, as much as the songs of the robins and redwing blackbirds. Dragonflies will deposit their eggs in these bodies of water and others will hunt back and forth across the surface. Small fish will be found in some of the ponds, providing food for the diving ducks.
In the next few weeks, especially after a warm spell, find a country road where you can drive slowly, keeping an eye out for those ‘bad’ potholes, but also looking for the ‘true’ potholes. They have rightly been called ‘duck factories’ and as such, demand our support and appreciation.
By Kate Crowley
Photos by Mike Link