Fewer loon chicks surviving because of climate change, researchers say

Karen Lund of Genoa, who does annual loon surveys with Johnson in northern Illinois, worries about those statistics. “It would be sad if there will be fewer loons and that people of the next generation might not see or hear them,” she said.

Loons once nested in Illinois, Indiana, Iowa and Ohio, but now they breed in Michigan, Wisconsin and Minnesota. They also breed in the New England region and a few northwestern states including Montana, but most nest in Canada. Illinois’s last breeding pair of loons was recorded in 1892 in Lake County. Reasons for their demise could include habitat destruction, pollution and other factors, Piper said.

Loons can live to be 30 years old, he said, but if they’re not producing enough chicks their numbers will keep dropping. Loons typically raise two chicks annually, enough to replenish their population.

“Overall, Wisconsin’s adult loon population has fallen an estimated 22% in the last 25 years,” Piper said.

The number of migrating loons in the Chicago region peaks around the end of March and beginning of April, but some will remain until early May before heading north.

“You can find them along the Lake Michigan shoreline (including at Montrose Beach) and lakes such as Maple Lake in DuPage County and Axehead Lake in Cook County,” Johnson said. “But the hugest numbers are on the Chain O’ Lakes, including on Pistakee Lake, Lake Marie, Bluff Lake and Channel Lake.”

While leading a recent trip around the Chain O’ Lakes area, Johnson said he and the participants heard loons yodeling as well as giving their haunting tremolo calls.

In breeding plumage, “the common loon has beautiful white reptilian spots on the back and a ruby-red eye,” Johnson said.

Each year for decades, Johnson, who is from Buffalo Grove, has picked one day in late March or early April to gather data on migratory loons in the Chain O’ Lakes area. He said he has noticed a drop in numbers. “But I wouldn’t say it’s precipitous.”

“Our highest count was 676 on April 6, 2013, but 401 this year is a good number too,” he said.

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