WESTERLY — Snowy owls are arriving in New England in large numbers this winter in an irregular phenomenon known as an “irruption.”
There are approximately 18 of the large, white owls currently in Rhode Island, and several of them have been seen along Westerly’s shoreline.
Rachel Farrell, a member of the Rhode Island Avian Records Committee, said the birds, from Ungava in far northern Quebec, are concentrated this year in New England and around the Great Lakes.
“This is the largest irruption since the irruption of 2013-2014,” she said.
Paradoxically, the reason the owls leave the North is the consequence of too many lemmings — the owls’ primary food.
“Lemmings have a bust-and-boom life cycle,” Farrell said. “This particular year, there was a boom. There was a very large population of lemmings. When the adult snowy owls see that there’s a large population of lemmings, they make more eggs. Instead of three to four eggs, they lay seven to 10 eggs, knowing that they’ll be able to feed their young right away.”
When the owlets grow into adults, the population outgrows its food source.
“There are not enough lemmings during the winter, so they come south for food, and that’s what’s happening this year,” Farrell said.
Snowy owls like the treeless terrain of beaches, because it is not unlike the Arctic tundra. Farrell said they are eating rodents and ducks.
“They will eat rodents, but they will also eat sea ducks, they’ll eat puddle ducks like Mallards, and one has been seen eating the blubber of a beached porpoise,” Farrell said.
The owls spending the winter here are a mix of young and old.
“There are a number of hatch year birds, but there are also some adults with them,” Farrell said. “They’re not all juveniles.”
The owls are expected to head back north in March. While they are here, Farrell is urging birders and photographers to keep their distance.
“It’s best to stay at least 300 to 400 feet away from snowy owls — all owls,” she said. “Typically, if the owl has its eyes open, it knows you’re there and their blood pressure actually rises when they think that there are humans. And humans are basically harassing them, still, for photos, to get that close picture, and want to get closer, and the owl may stay still, or it may flush.
“Photographers and birders think if the owl stays there when they get so close, ‘Oh it doesn’t mind my presence.’ That is completely wrong. They know you’re there and if they don’t have energy from that day’s feeding, they may not flush until you’re right on top of them. If the eyes are open and the owl is looking at you, you have already started to disturb the owl.”