IRON MOUNTAIN – The predictions of a slack year for visiting snowy owls may have been a bit premature.
When owls did not appear in October and early November, it seemed to indicate that these iconic raptors might not make the trip from the arctic tundra and polar ice this year.
Turns out they were running or flying late, said Ryan Brady, natural heritage conservation biologist at the Wisconsin Department of Natural Resources.
The rate of snowy owl sightings has accelerated dramatically in recent weeks, especially in eastern Wisconsin, Brady said in his weekly report. Other owls have ventured as far south as Tennessee, Kansas, Colorado, and Virginia.
“After the slow start, snowy owls have invaded Wisconsin, bringing at least 72 owls to 30 counties by December 1, 2021,” Brady wrote in the report. âAll but a few have arrived in the past two weeks. This total exceeds the 46, 34 and 21 found on that date in 2018, 2019 and 2020, respectively, but is below the 124 recorded on that date in the year of the 2017 irruption. â
These influxes of snow owls were once thought to be an indication that populations of lemmings – the main prey of birds – had crashed into the north, forcing birds in the south to find food. But Brady said on Friday that the irruption years often signaled the opposite: Adult owls have responded to an abundance of lemmings by hatching larger clutches, or possibly even raising two broods.
They can produce 10 or more young birds if conditions are right, which will lead to a wave of first-year snowy owls to disperse as fall arrives, Brady said.
The most recent outbreaks have been dominated by year-old birds, sometimes second-year owls, with few full adults. Young snowy owls have bold scalloped markings, which females retain while mature males turn almost completely white.
These young birds face uncertain prospects for coming to Wisconsin and the Upper Peninsula. They don’t know the best hunting areas, they have little or no experience with humans or urban areas, and they’re still developing their skills in finding and catching prey, Brady said.
They flew over Canada’s boreal forest, possibly even Lake Superior, to reach the region, Brady said.
“It’s a lot of energy spent” he said.
Once here, they can gravitate to areas of open water that offer prey for waterfowl or gulls and other birds, even muskrats. They will look for large open fields similar to the tundra that could provide rodents and rabbits. The heaviest of North American owls, snowies are capable of taking down a wide range of animals.
Some may even try to live in the city or the suburbs to live off pigeons or garden rabbits, Brady said. Airports are a great place to spot snowy owls, as they have large open areas and good habitat for prey.
Still, some of these visiting owls will fail to thrive here. Each year, some are taken to wildlife rehabilitators, some are found dead.
The truth is, Brady says, that about 70% of all young raptors don’t survive their first year, not just owls. The percentage may be even higher in songbirds, he added.
This year’s snow owls don’t appear to be arriving in bad shape, although some have already died or need treatment, he said.
The public may also get the idea that snowy owls are active during the day, which is referred to as being diurnal, so be concerned when you see that you are not moving that they may be weak or sick. .
Yet in most cases, snowy owls seen during the day sit still – perch – often on the ground in an open field. Like most other owls, they prefer the night and won’t become truly active until late afternoon, in the twilight of winter or in the slanting sun, Brady said.
Snowy owls, out of necessity, have learned to function during the day, as they nest in territory which in summer may be little or no darkness.
While the Iron Mountain area is not ideal for snowy owls – they prefer areas open to forests, Brady explained – the area usually receives a few reports once an influx begins. In November 2017, one of them landed on the hood of a vehicle waiting at the drive-thru at Jimmy John’s sandwich shop in Iron Mountain. And in January of this year, former wildlife rehabilitator Phyllis Carlson tended to a snowy owl before releasing it back into the wild.