Field Notes: Call for Counters
Hunkered down amid sedges in the predawn darkness, I wait. It's early April, which means it's cold. Silence fills my ears. Minutes pass slowly. I feel like Linus waiting for the Great Pumpkin. The first birds I hear are a pair of Canada geese, honking their way across the marsh. Then, a spectacular reaction: A string of high-pitched, staccato notes, like frantic music from a deranged trumpeter, with the rhythmic texture of a spoon raking along a rusty metal washboard . . . a sandhill crane's unison call.
A similar call answers promptly. Soon the marsh erupts with a fervent clamor. I dutifully record three breeding crane pairs in my notebook.
In marshes in Wisconsin, Michigan, Illinois, Iowa, and Minnesota, more than 2,400 crane counters are doing the same as part of the Annual Midwest Crane Count. The count began in 1976 as a high school biology project in Wisconsin. In 1981 the International Crane Foundation in Baraboo, Wis., adopted it. Today it is one of the largest and longest-running single-species surveys in the world.
The rules of the count are simple: Be at your assigned marsh before 5:30 a.m., when sandhill cranes begin vocalizing and foraging for tubers, snails, frogs, and insects. Write down every crane you see or hear, and send the results to the ICF.
Nearly three decades of data tell a remarkable story about the sandhill crane's triumphant return from near extirpation in the upper Midwest.
The tale begins a century ago, when the population crashed due to unregulated shooting and wetlands destruction. Whereas sandhill cranes were common throughout Minnesota prior to settlement, by the mid-1930s the population had dropped to three dozen breeding pairs-all in the northwestern corner of the state.
But sandhill cranes came back, due partially to the protections provided by the Migratory Bird Treaty Act, but mostly to cranes' ability to adapt to foraging in farmland.
A DNR survey in 1979 showed the sandhill crane popu-lation had grown to about 50 breeding pairs in northwestern Minnesota. The same survey also noted a second population of about 25 breeding pairs in east-central Minnesota.
Today an estimated 650,000 sandhills live throughout North America-making them the most populous crane species in the world. Birders report seeing cranes throughout southern, central, and northwestern Minnesota. But no one knows for sure how many sandhill cranes are in Minnesota.
"Listening for sandhill cranes as the sun rises on an early spring morning can be an exciting way to start a day," says Joan Galli, DNR nongame wildlife specialist. "We encourage Minnesotans statewide to participate in this event as we know such citizen scientists can be a great help in filling the gap in our knowledge about the present-day distribution and abundance of these birds in Minnesota."
ICF biologists would like to get an accurate estimate of the state's sandhill population. So far, only Morrison and Wabasha counties have participated in the annual survey.
"We'd like to get more crane counters in Minnesota," says ICF naturalist Brandon Krueger. "It's important to keep tight tabs on species like cranes that are indicators of wetlands health. Even though they've adapted to farm habitat, they still feed a lot in marshes, and they nest exclusively in wetlands. If you don't see or hear cranes in a marsh, that means the ducks or warblers in that marsh could be in trouble too."
To learn more, visit the International Crane Foundation.
To join this year's count, April 16, e-mail firstname.lastname@example.org or call 608-356-9462, extension 127.
Gustave Axelson, freelance writer
For more information on Sandhill Cranes, see MN DNR Nature Snapshots.