Last winter, a group of researchers set out to capture a snowy owl in Maine. Their goal was to outfit the bird with a high-tech tracking device so it could become a part of Project SNOWstorm, a collaborative research project to learn more about snowy owls and their mysterious winter migrations.
Despite their efforts, the researchers were unsuccessful. That season, Project SNOWstorm captured and placed GPS transmitters on snowy owls from Maryland, New York, Pennsylvania, Michigan, Wisconsin and Ohio, but the “snowies” hunting in Maine that winter remained elusive and returned to their breeding grounds in the Arctic that spring without being tagged.
This winter, however, Maine finally made its way onto the Project SNOWstorm map.
So far, two snowy owls captured in the Pine Tree State have been outfitted with GPS transmitters to join the ranks of Project SNOWstorm under the names “Brunswick” and “Casco.”
“Through this work, we are gaining a better understanding of the lives of these majestic birds,” said Lauren Gilpatrick, a wildlife biologist with the Biodiversity Research Institute of Portland, which partnered with Project SNOWstorm to capture and outfit the two Maine owls. “Being involved with Project SNOWstorm has personally been a career highlight for me. Getting to work with such a large group of some of the nation’s top owl experts is a great honor.”
Project SNOWstorm was established in the winter of 2013-2014 in response to one of the largest snowy owl irruptions ever recorded. That winter, snowy owls migrated from their breeding grounds in the Arctic south to Canada and U.S. in large numbers, delighting wildlife photographers while worrying airport administrators.
Snowy owls are attracted to airports because their open terrain closely resembles the Arctic tundra they call home. Unfortunately, they pose a serious threat to aircraft and passenger safety. The large, white owls weigh an average of 5 pounds, with a wingspan of 4 to 5 feet. A collision can cause significant damage to an aircraft and be fatal for the bird.
The Federal Aviation Administration ranks the snowy owl as the 17th most hazardous bird to aircrafts in a list that includes 66 bird species and groups. Because of their large size and their tendency to fly low to the ground, snowy owls can cause serious damage to aircrafts. On rare cases, bird-aircraft collisions have resulted in emergency landings and crashes.
“Snowy owls are big birds, and what makes them even more hazardous [to aircrafts] is the slow, low-flying behavior and their reluctance to leave,” Adam Vashon, a wildlife biologist for the United States Department of Agriculture Wildlife Services in Maine, said.
USDA Wildlife Services often assist airports in dealing with snowy owls and other types of wildlife that are posing a threat to aircraft and passenger safety. The program’s central mission is to help solve human-wildlife conflicts with an integrated approach, using multiple methods on a case-by-case basis. In many cases, the wild animal is trapped and relocated an area where it won’t cause problems. In other cases, measures are taken to keep the animal away, such as the construction of a fence around an area. But in some cases, especially when the animal is threatening human safety, Wildlife Services decides the best way to resolve the issue is to kill the animal.
“There are dozens of very serious bird strikes [with aircrafts] across the country each and every year,” Vashon said. “We’ve been successful at reducing them.”
For the tracking project, snowy owls “Brunswick” and “Casco” were captured while hunting for rodents at southern Maine airports. Bangor International Airport also recently announced at an Airport Committee meeting that they also will participate in Project SNOWstorm, if an eligible owl is captured at its facility this season.
Wildlife Services captured “Brunswick” at the Brunswick Executive Airport on Jan. 11, using what’s known as a bal-chatri trap, which consists of a wire dome placed over live bait — typically a rodent or small bird. The dome is covered with microfilament nooses that catch the owl’s feet when it comes down to take the bait. This method is commonly used by biologists to catch birds of prey and does not harm the animal if monitored closely by someone who is trained to use the trap.
“It worked like a charm,” Vashon said.
In collaboration with the Biodiversity Research Institute, the owl was carefully inspected. It was a female and healthy — a perfect candidate for Project SNOWstorm.
After fastening a silver, numbered band around the owl’s leg, BRI outfitted the bird with a high-tech GPS transmitter — a piece of equipment that costs roughly $3,000. The next day, the owl was released at Rachel Carson National Wildlife Refuge in Wells.
The GPS transmitter, created by New Jersey company Cellular Tracking Technologies, was constructed specifically to track birds movements in detail. It records a bird’s location each 30 minutes using satellites, then stores the data to be sent by cellphone tower to researchers each week.
“They’re solar powered, so barring some sort of mechanical failure they should last a long time,” Scott Weidensaul, co-founder of Project SNOWstorm, said. “They’ve lasted seven to eight years on golden eagles. We’re really hopeful we’ll get the same kind of lasting data from them.”
Project SNOWstorm, which began with the snowy owl irruption of 2013-2014 and is funded entirely by public donations, has deployed 42 of these lightweight transmitters on snowy owls captured in the Northeast and Midwest over the past three years, being careful to only select healthy owls as carriers.
“In many respects, almost every owl we’ve put a transmitter on has surprised us in some fashion,” Weidensaul said. “We’ve seen some really interesting individual differences in behavior.”
For example, Project SNOWstorm researchers have learned that some snowy owls on the coast travel out over the water at night to feed on waterfowl and seabirds, while other snowy owls hunt exclusively on land, preying on voles, rabbits and mice. Some snowy owls return to the same hunting ground each winter and barely move from that spot, while others seem to have wanderlust, flying for hundreds of miles and only stopping for short periods of time. Their research also has shown that neighboring snowy owls will respect each other’s hunting territories, and that they tend to become more active around dusk.
“One of my colleagues has said — and I think this is really true — the lives of individual birds are fascinating,” Weidensaul said. “When you have the opportunity to study them week after week, year after year, you can see these, I wouldn’t hesitate to say, personalities come through. They’re very individualistic.”
The transmitter is fastened to the bird with a flexible harness made of woven Teflon, which is hidden by the owl’s thick coat of white feathers.
“It’s incredibly tough and incredibly gentle material,” Weidensaul said. “I’ve put a bunch of these transmitters on [owls], and it’s a long, fiddly, meticulous process. We’re very aware of the fact that the bird is going to wear the harness and transmitter the rest of its life unless we catch the bird again, which we do in some cases.”
The entire contraption weighs less than 3 percent of the owl’s weight.
“It it goes on properly and fits well, it’s absolutely not a problem for the bird,” Weidensaul said. “I can actually say that with confidence.”
Laval University in Quebec has studied snowy owls carrying similar transmitters for about 25 years, comparing their survival and reproductive rate to snowy owls not carrying transmitters. They found no difference in their survival rate, Weidensaul said.
“And birds with transmitters had slightly more chicks on average,” Weidensaul added. “Their joke is that it’s the ‘bling effect.’”
Maine’s second snowy owl to become a part of Project SNOWstorm was captured by Wildlife Services at the Portland International Jetport on Feb. 22. Four snowy owls were seen at the airport that day, but only one went for the bait in the bownet trap — a device that includes live bait and a remotely controlled net that drops over the owl.
“It’s a good safe technique,” Vashon said. “A hoop throws a net over the bird. It’s a technique all raptor research biologists use. It may look obvious to you, but it fools them.”
Named “Casco,” the large female owl was outfitted with a leg band and transmitter and placed into a large dog carrier to be brought by truck to a vast complex of blueberry barrens in Cherryfield, about 150 miles northeast of where it was captured.
“I’ve never seen an owl this mellow,” Matt Ewing, a wildlife specialist with Wildlife Services who teamed up with Gilpatrick for the release, said.
“In the hand, snowy owls are pretty calm compared to falcons or eagles,” Gilpatrick said. “You don’t even have to use a hood on snowies, and they still relax in your lap. … Snowy owls have an altogether different look in their eye than a falcon or eagle.”
Gilpatrick lifted the owl slowly from the carrier and inspected the bird’s GPS transmitter — a dark square located high up on its back. Then, with one hand grasping the owl’s legs and the other supporting its chest, Gilpatrick swung the bird back, then forward several times before releasing it into the air.
Free again, the “Casco” flew across the red fields and disappeared over the trees.
The public can follow “Casco” and “Brunswick” as well as the other snowy owls involved in Project SNOWstorm at projectsnowstorm.org. On the website, the birds’ locations generally are updated once per week.