SOUTH PORTLAND — A steady stream of cars drove around the loop at the end of Jetport Plaza Road on Wednesday, each carrying people who hoped to see the snowy owls that have taken up residency there this winter.

The owls are here during an irruption – a cyclical population explosion that has increased the number and range of younger snowies that typically venture south in winter from their nesting habitat on the Arctic tundra. Researchers say that habitat and the owls are threatened by climate change.

No-parking signs kept observers from stopping near the emergency entrance to the Portland International Jetport, but a few people had parked elsewhere and walked to the fence line of the vast airfield.

Kathie Harper, a birder who lives in Cumberland, drove down Wednesday to shop in the Maine Mall area and stopped by the jetport for a possible snowy sighting. She wasn’t having much luck with her binoculars, but she gladly shared them with Vicky Miville and Sherry Parkinson, who came all the way from the Augusta area to see one of the captivating, mostly white owls with golden eyes.

“I can’t tell whether I’m looking at a mound of snow or an owl,” Harper said. “I wish I had a scope.”

Jetport officials say the owls and their human admirers are causing problems for the largest airport in southern Maine, The Associated Press reported. Spurred by news reports and photos posted on social media, some birders are parking illegally and creating safety hazards.

In particular, jetport officials said they worry that onlookers may disturb the owls and scare them into the paths of planes. Assistant Airport Director Zach Sundquist said there’s an observation area with parking south of the airport near a hangar.

As many as eight snowy owls at a time have been seen at the jetport this winter, said Adam Vashon, a wildlife biologist with the U.S. Department of Agriculture’s Wildlife Services. That’s the agency that helps to control the snowy owl population at Maine’s airports to ensure the safety of both air traffic and owls.

ELEVEN OWLS RELOCATED

Vashon’s agency has captured and moved 11 snowy owls from the jetport this season, he said. Since 2014, it has captured and moved more than 50 snowy owls and seen fewer than 2 percent of the birds return.

Vashon agreed that snowy owls are “fascinating birds,” but he said the public must understand that disturbing the birds before they can be caught and relocated can be dangerous to both humans and owls.

“Snowy owls that are startled or disturbed may unintentionally fly directly into the path of incoming or outgoing aircraft, causing possible human injury, damage to the aircraft, and death of the bird,” Vashon said.

To learn more about snowy owls, Vashon’s agency works with the Biodiversity Research Institute, a nonprofit environmental consulting group in Portland that bands and places solar-powered GPS transmitters on some of the birds. The institute is a partner in Project Snowstorm, a 4-year-old research program that’s studying snowies that are caught at airports across the country and relocated.

“It’s a big year for the snowy owl in Maine,” said Scott Weidensaul, an author and naturalist who co-founded Project Snowstorm.

A snowy owl takes flight from a navigation pole at the Portland International Jetport on Tuesday. Several snowy owls have returned to the airport causing traffic problems on the southern end of the property as birdwatchers park illegally.

“We get snowy owls in the Northeast and throughout the northern Midwest every winter,” Weidensaul said, but this season they’ve been spotted as far south as Texas, Oklahoma and South Carolina.

The digital transmitters that are placed on the snowies use satellite and cellphone technology to track everything from flight speed and air temperature to ground movements and sleeping habits.

In early December, a robust young male owl was captured at the jetport, outfitted with a $3,000 transmitter and moved to the Rachel Carson National Wildlife Refuge in Wells. Unfortunately, it was electrocuted a few days later when it landed on a transformer, Weidensaul said.

Other tracking efforts have been more successful. One female snowy that was caught at a Michigan airport and outfitted with a transmitter was subsequently tracked to North Dakota, up into the Arctic and to Saskatchewan, Weidensaul said.

Most of the snowies seen in southern Maine are young males and females, born last summer following a cyclical burst in the Arctic population of lemmings, their favorite food, Weidensaul said. When lemmings and other rodents become scarce in the Arctic, the younger owls head south in search of food. Male snowies, which are smaller and less aggressive than females, are forced to fly even farther south.

SNOWY OWLS UNDER THREAT

Researchers believe snowy owls are under increasing threat across the northern hemisphere, primarily related to the impact of climate change on Arctic habitats, Weidensaul said.

Last fall, the International Union for Conservation of Nature elevated the snowy owl from its “least concern” category to “vulnerable” – one step away from endangered.

The snowy owl’s global population was previously estimated at 200,000 individual birds, including across Europe and Russia, but recent estimates dropped below 30,000 individual birds, to about 14,000 pairs and possibly as low as 7,000 to 8,000 pairs, according to the conservation group’s Red List.

“Drivers of the decline are uncertain but likely include climate change effecting prey availability, as well as collisions with vehicles and infrastructure,” the Red List says.

In particular, researchers believe warmer temperatures and reduced snow pack have contributed to lemming population collapses in Greenland, Norway and Sweden.

“If that continues to happen, we could start to see problems for snowy owls,” Weidensaul said.

Snowy owls aren’t listed as endangered or threatened in the United States, but they are protected from hunting and other human intervention under the Migratory Bird Act.

MICE, VOLES AND WATER BIRDS

In Maine, where snowy owls have been spotted from Acadia National Park to Biddeford Pool and beyond, the raptors are snapping up rodents, such as mice and voles, and some water birds, Weidensaul said.

They’re attracted to fields, marshes, airports and other open areas.

“The jetport is probably the most reliable place to see them,” said Laura Minich Zitske, a wildlife biologist at Maine Audubon. “They like wide open places, like their home on the tundra.”

What snowy owls don’t see much of on the tundra is people, though native people in Arctic regions are allowed to hunt them for food. Zitske and other wildlife experts say people who are fascinated by the owls should avoid getting too close or engaging with them at all.

Throwing food or other items at them to get them to fly is against the law. Feeding snowies may lead them to associate humans with food and prove detrimental to the owls and people in the future. Young owls in particular can be exceptionally curious and trusting of people.

“In general, I think people are respectful, but there are always exceptions,” Zitske said. “It’s best to avoid disturbing them in any way. Especially around the jetport, where there are a lot of safety issues. Keep your distance and respect posted signs.”

Gene Lagomarsino was at the jetport on Tuesday, along with other photographers and birders. The North Yarmouth resident enjoys photographing wildlife in his spare time, and he stopped to shoot some snowy owl photos while on the road for his sales job.

“It was a real treat,” Lagomarsino said Wednesday. “I had never seen a snowy owl before. The bird cooperated and flew from a snow bank up to an airport apparatus, so I got some great full-body shots.”

Lagomarsino said he went back to the jetport Wednesday, hoping for a repeat experience, but it was a short visit.

“They kicked me out really quick,” he said.

Kelley Bouchard can be contacted at 791-6328 or at:

kbouchard@pressherald.com

Twitter: KelleyBouchard

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