070821.FocusOnNature

A pair of Eastern bluebirds chose this nesting box at the Nature Education Center in Fifield in June 23, 2020, raising a family of five. This year no bluebirds nested in any of the Center’s 20 nesting boxes, likely due to a major die off migratory birds caught up in extreme weather events that occurred during spring migration.

There is something missing in our Northwoods this year, Eastern bluebirds along with a few other short-distant migrants like Eastern phoebes. Both species have returned to nest at our Nature Education Center in Fifield as long as I can remember, but this year was different — they didn’t show up.

Several people have asked me, “Where are all the bluebirds?” So, I began to wonder what happened to some of our migratory bird species that return like clockwork every spring to our Northwoods but are missing from our landscape this spring and summer.

Bluebirds do not leave the U.S. during fall migration except for a few that winter in northeast Mexico. They go only as far south as needed to find food and mild winter weather that has more and more frequently included southern Wisconsin. But most of our bluebirds head to Missouri and Arkansas directly south of us, but apparently unusual weather events this past winter had a big negative impact on the birds in those areas.

I found out that hundreds of thousands of Eastern bluebirds died in February during harsh winter weather to the south of us. Snow, ice and cold weather killed bluebirds and other early migrants in a wide swath from Oklahoma to the East Coast according to a Star Tribune article by Jim Williams. He reported that newspapers throughout that area said Eastern bluebirds and other early spring migrants froze or died from lack of food and water. And, that is likely why you are seeing fewer or no bluebirds in our area this year.

This last spring, Williams found no bluebirds in the three dozen boxes he manages in Minnesota. Also, I have no bluebirds in the 20-some nest boxes I monitor in Fifield in Price County, Wisconsin. Ken Boness and his brother around Butternut, Wisconsin, in Ashland County reported they had no bluebirds in their nest boxes and the same was true for Bill Hoffman at Brantwood, Wisconsin, in southern Price County; he didn’t have any phoebes either.

My sub-permittee bander Ann Wick at Black Earth in Dane County, Wisconsin, who has banded nestling bluebirds for over 25 years, reported to me that for the first time ever her bluebird breeding pair numbers are way down, by one-third! Some her nesting pairs successively overwintered in their breeding territories in southern Wisconsin because they had no need to migrate south as they apparently found adequate food, water, and shelter there. She knew this because she had banded some of these birds.

Ann too feels an extended cold/freezing rain spell that hit the southern states earlier this year may have contributed the loss of some of her birds that migrated south. Many of her blue birding friends in the central and southern U.S. reported finding large numbers of dead adults when they checked their nest boxes this spring, undoubtedly due to unfavorable weather and perhaps lack of food.

Wisconsin DNR Conservation Biologist Ryan Brady reported that he had many calls and messages about “missing bluebirds” this past spring. He stated that some of the short-distance migrants likely took a big hit due to the cold/ice in southern U.S. this past winter. Bluebirds, phoebes and hermit thrushes appear to be the worst hit.

Joe Neal, a retired wildlife biologist with the U.S. Forest Service, said that Arkansas experienced a massive die off of Eastern bluebirds due to some unusual winter storms. “Some people reported checking their bluebird box and finding the birds dead,” Neal said. “Everyone across the state started looking at their bluebird boxes and found many dead birds. They were huddled for warmth and safety in bluebird boxes, and it got too cold. They probably also didn’t have enough food. Some people found them staggering out of boxes. They couldn’t fly. They ran out of energy.”

Neal said the birds’ average wintering range has been moving north. But that can be deadly when there is a severe cold spell like they had. “Those birds trying to adapt to climate change by moving north get caught in one of these supermax storms,” Neal said.

If there is any good news in this story, it is that we usually don’t have severe, prolonged cold bouts every winter. History has shown that bird populations eventually tend to quickly bounce back from these kinds of setbacks, if they don’t happen in successive years. But we are coming to realize that normal weather patterns aren’t normal any more as our climate changes.

I, for one, am hoping that some bluebirds will find some of my nest boxes next spring and a phoebe will be nesting under the eve of our barn roof once again. Only time will tell.

The private Nature Education Center in Fifield operated by Tom and Mary Lou Nicholls is open seasonally by appointment only. Nicholls can be reached at nicho002@umn.edu.

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