MARQUETTE - For centuries, observers across the northern section of the country have marveled at the sudden, significant and sporadic winter movements of several species of birds into their cities, towns and rural areas in what scientists call "irruptions."
In some cases, the birds in these seasonal movements are motivated by the lack of sufficient food supplies - including pine cone crops - in Canada and points farther north. In other instances, scientists don't have enough biological information to clearly understand the reasons why the irruptions occur.
The bird species irrupting are not typically found in large numbers south of the Canadian border in non-irruptive years and can include several types of "winter" finches, including white-winged and red crossbills, common and hoary redpolls and pine and evening grosbeaks.
But most spectacular in the eyes of many birdwatchers, and non-birders alike, are several irruptive species of owls which "invade" most prominently the northern states, usually on somewhat regular cycles, including northern hawk owls, great gray owls, and especially snowy owls.
During the winter of 2011-12, the country saw a banner year for snowy owl irruption. Dozens of the beautiful white birds with golden eyes were seen throughout the Upper Peninsula and across the country, as far west as Hawaii.
This winter, the phenomenon is repeating itself in many states including Wisconsin, where the Department of Natural Resources recorded nearly 250 of the birds by the end of January in nearly all parts of the state.
"Though not unprecedented, this does rank among the largest record irruptions in recent memory, now even surpassing the big flight of 2011-12," DNR officials said in a monthly report.
Dawn Hewitt, managing editor of Bird Watcher's Digest, said snowy owls have been reported in record numbers since mid-November across New England and throughout the Midwest.
"Data going back to the late 19th century show that snowy owls irrupt in winter every 3.9 years, on average," Hewitt said in an online article.
In the U.P., a few snowy owls have been seen this winter in a handful of counties including Marquette, Dickinson, Houghton and Delta counties. Some owls drift on ice floes in the Great Lakes. They sit on top of poles, roofs and other structures.
"Several were spotted in the Marquette area in December and early January, but appear to have moved on," said Jerry Maynard of the Chocolay Raptor Center in Chocolay Township. "I have received reports of 'snowies' being spotted as far south as the Carolinas this year, with numerous reports from southern Michigan."
Some of the snowy owls, which feed on rodents and birds, were found at the Gerald R. Ford International Airport in Grand Rapids earlier this winter. The birds have traveled as far south as Texas and California in some years.
"They have become a problem at airports where they like to hang out because it is like the Arctic tundra; they are big enough to pose a hazard to planes," Maynard said. "Some airports have capture and transport programs, while others shoot them, until the birders get wind of it and protest."
The snowy owl found at the Honolulu Airport during the 2011-12 irruption winter was the state's first record of the species. The bird was shot.
Often, the far-traveling snowy owls are in poor condition, suffering from lack of food and dehydration, when they reach these places far south from their Arctic breeding grounds. Last winter, Maynard had a snowy owl brought to the rehabilitation center that was severely emaciated.
"We were unable to save it and had it mounted for use in educational programs," Maynard said.
Earlier this month, a snowy owl was seen by a birder on the ice next to the Shiras Steam Plant in Marquette. The owl was standing on the ice watching a group of common mergansers and goldeneyes, looking for a meal.
One of the best places in the U.P. to find irruptive owl species is in Chippewa County in several places south of Whitefish Point and east of I-75. There are birders who make regular trips to the area and excursions are organized through the Whitefish Point Bird Observatory in Paradise.
Northern hawk owls and great gray owls, which like snowy owls, can be seen during daylight hours are seen there with some regularity each winter.
In recent weeks, a handful of snowy owls were found in the area in some of the traditional places to see the birds, including roads through open country around Rudyard. A great gray owl had been reported in the area, though birders didn't find it on their most recent trip.
Great gray owls are North America's largest owls, with wingspans measuring up to five feet. The big round faced birds have small golden eyes. They are even larger than the more familiar great horned owls, which are common resident species of the area which don't migrate.
John Pepin can be reached at 906-228-2500, ext. 206. His email address is firstname.lastname@example.org.