POLSON — Another year and another historic irruption of snowy owls.

Just not in Polson.

Parliaments of the Arctic migrants have maintained a seasonal roost in the Mission Valley the past two winters, but there have been no confirmed sightings of them in the area this year.

“I’ve looked several times,” said Denver Holt of the Owl Research Institute in Charlo. “I’ve tried to track down some of the reports and haven’t seen anything.”

“It’s certainly not like the last two years,” agreed Jim Rogers, president of the local chapter of the Audubon Society.

Although largely absent from Montana, the owls have been seen in almost record numbers from the Great Lakes to the East Coast of the United States.

The crowdsourcing birdwatching website, eBird, has documented hundreds of “snowies” from Wisconsin to New England and as far south as North Carolina (and possibly Bermuda!).

Rogers has fond memories of an irruption of similar magnitude that happened several years ago, when he led a birdwatching trip for local school children.

“That irruption, around 2006, there were over 50 birds,” he said.

More recently, the area has played host to an estimated 8-14 birds the past two winters, with the owls establishing the rooftops of Polson’s Skyline Drive as one of their preferred hangouts.

Despite all the attention that the birds attract, scientists are unsure of the factors that influence their fickle migration habits. Holt reported that it was “hard to say” whether the groups of owls that had congregated in Polson the last two years were the same individuals or what has led thousands to suddenly gravitate toward the East Coast.

Rogers echoed that uncertainty.

“I don’t think anybody still has a clue as to why they show up when they do,” said Rogers.

Though the owls are a favorite of birdwatchers, Rogers says that there are still plenty of interesting species around to capture his attention.

“If anything, maybe the milder weather has allowed other raptors to visit,” said Rogers, reporting that he’s seen unusally high numbers of kestrels and goshawks. “There’s never a shortage of birds.”