Researchers are taking advantage of a population boom of snowy owls to study the arctic birds that have invaded the Northeast.
Occasional visitors to New Jersey, the owls have been seen in record numbers this year along the East Coast as far south as Florida, likely driven by an especially good breeding season.
Scientists launched an impromptu study called Project Snowstorm last month to capitalize on what they are calling a once-in-a-lifetime opportunity.
They captured and attached solar transmitters to a handful birds, including one nicknamed Assateague that has been spending the winter in South Jersey. Ultimately, they want to track as many as 24 owls from Wisconsin to New Jersey.
“Nobody saw this coming. By the first week of December, there were snowy owls all over the Northeast,” said lead researcher Scott Weidensaul, of Schuylkill Haven, Pa. “We decided to squeeze as much science out of this event as we could.”
David Brinker with the Maryland Department of Natural Resources mobilized a team of owl experts. His group raised $20,000 through crowd-funding to buy transmitters.
Already the results are starting to illuminate the secret world of snowy owls.
Researchers caught and tagged a snow-white male named Assateague on Dec. 17 in Maryland. Two days later, he flew to Cape Henlopen, Del., before crossing 38 miles of open water on the Delaware Bay to Stow Creek.
Assateague then flew down the bay to Reeds Beach in Middle Township, where it spent a week, making nightly sorties over open water — probably to hunt for ducks, Weidensaul said.
Assateague proceeded along the Tuckahoe River to the Great Egg Harbor Bay and Atlantic City, where it roosted overnight at the Steel Pier. Daily it has moved farther north to Barnegat Bay, where it has settled for weeks.
Another bird, nicknamed Philly, spends each night hunting the median strip of I-95 just outside Philadelphia International Airport. At one point, its transmitter suggested it was sitting in the middle of the highway, making researchers fear it had been hit by a car, but the bird was fine, Weidensaul said.
The transmitters record the coordinates of the bird at regular intervals and dump the stored data whenever possible via cell towers.
Researchers are screening road-kill birds for toxins and taking blood samples from captured birds to study their overall health and genetics.
Weidensaul said his study could help researchers follow these individual owls over the span of years, capturing a wealth of information whenever the owls fly within range of cell towers.
This could help them understand their migratory patterns — why some travel so far while others stay put.
The owls spend the summer raising their young on the tundra of the high arctic. In food-poor years, they might raise one or two chicks, if any. But in food-rich years, they lay as many as 16 eggs, he said.
“These owls are so highly nomadic. We might have overestimated their population,” he said. “If you count all the owls breeding in Alaska, Greenland and Canada, the assumption is these are all discrete populations. But they could be the same owls moving around the circumpolar region.”
Studying the birds could help scientists understand climate change, he said.
“This is a species that will be affected by climate change more quickly than any other bird because they breed at such a high latitude,” he said.
Lemmings, the owl’s favorite food, survive the winter by making tunnels under heavy insulated snow, he said. And some researchers in Norway have observed a flattening of the boom-and-bust population cycle of these prolific rodents, he said.
Mike Crewe, program director at New Jersey Audubon’s Cape May Bird Observatory, said the research could shed light on the less-understood wintertime habits of these birds.
“It’s early days but what’s coming out is interesting,” he said. “These birds are obviously out hunting the water at night. They’re spending time sitting on buoys in the channels.”
Crewe said it might seem surprising that a snowy owl would hunt open water for food.
“It’s a most extraordinary thing to imagine. Taking a duck out of the water is a risky thing for an owl,” he said.
The owls likely are finding sleeping ducks in the marshes, he said. He has seen an owl devouring a black duck in Stone Harbor.
Research aside, Crewe said many people simply have enjoyed watching these beautiful, resilient birds at places such as Cape May and the Edwin B. Forsythe National Wildlife Refuge.
“When they first turned up, I was like a kid with a new toy. I’ve calmed down a little bit,” he said.
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