(CNN) -- Two snowy owls injured by the downdraft of jets taking off in Boston have been released in a safer place where the likes of saltmarsh sparrows and piping plovers flutter amid marshes, bogs and beach dunes.
The pair were released Monday morning at Parker River National Wildlife Refuge on Plum Island in northeastern Massachusetts, after nearly eight weeks of treatment and rehabilitation, said Dr. Flo Tseng, director of the wildlife clinic where the birds were treated.
The yellow-eyed, white birds were taken in March to the Tufts Wildlife Clinic in North Grafton, where one was treated for soft-tissue wounds and the other had lifesaving surgery for a broken wing, said Tseng.
The owls were rescued by Norman Smith, director of the Massachusetts Audubon Society's Blue Hills Trailside Museum, after they were injured at Boston Logan International Airport.
The owls have been a concern for decades at the airport, where authorities use nets to catch the birds before relocating them, Smith told CNN in December.
A greater number of owls have been reported at the airport this year, Tseng said. Logan officials have captured and released more than 100 snowy owls this winter, as opposed to just 10 owls last year, she said. The influx is possibly due to an abundance of prey. Logan Airport's likeness to the tundra makes it a favorable place for the birds to land, but a dangerous place to fly, Tseng said.
Tufts Wildlife Clinic, part of the Cummings School of Veterinary Medicine at Tufts University, has treated six snowy owls this year. The clinic has a 100-foot flight pen that's used for conditioning, a key part in the owl's recovery, she said.
"We go in there and we bug them. We walk down to the end where they're perched and they'll fly down to the other end. So we end up exercising them," Tseng said.
Although snowy owls are not an endangered species, their numbers are declining and nobody knows the actual population of these birds, said Smith.
Tseng said the rise and fall in the number of owls they treat each year varies.
"We try not to get attached because they're wild animals and many wild animals don't make it. It's really hard for them in captivity," she said.
Tseng said she believes these two owls are the last the clinic will see this season, because most have already migrated back toward the Canadian Arctic. "They'll probably spend a little bit more time hanging around Plum Island, building up strength before going up north."
CNN's Allie Malloy contributed to this report.