Just what do Snowy Owls do in winter? Where and how do they hunt? And how far do they roam? These are questions that author and bird bander Scott Weidensaul and Maryland ecologist and Project Owlnet founder David Brinker hope to answer soon. They’re the leaders of Project SNOWstorm, a new crowd-funded tracking effort organized with help from Project Owlnet, Hawk Mountain Sanctuary, and other organizations.
Shortly after this winter’s Snowy Owl invasion began, the investigators started attaching solar-powered cellular transmitters to owls captured in eastern and Great Lakes states. The transmitters relay the birds’ positions to cell-phone towers, allowing the researchers to track the birds and study their behavior, hunting habits, and range size.
The team has fitted 14 owls with transmitters since December. The latest, pictured at right, was tagged yesterday by Weidensaul. It was caught at the Philadelphia airport and relocated about 50 miles west to Lancaster County, Pennsylvania. The researchers tagged another bird in Delaware Sunday night. It has now moved across Delaware Bay into New Jersey.
“Our goal is still to get between 20-25 owls tagged this winter, and while it’s an ambitious goal, we should be able to do it,” Weidensaul says.
So far, birds in New York, Maryland, Pennsylvania, Wisconsin, Minnesota, Massachusetts, and Delaware have received transmitters. Owls in Ohio or Michigan may also be tagged soon.
One of the project’s birds, a young male the team named Philly, died on January 29. He was captured at the Philadelphia airport on January 9 and released in Lancaster County but returned to the airport, where he was struck by a cargo plane before wildlife officials could relocate and capture him.
“We always knew that there was a good chance we’d lose one or more of our tagged owls this winter,” Weidensaul wrote on the project’s website. “The Snowies we’re seeing in this irruption are largely young birds, and that inexperience — combined with the natural naiveté of Snowy Owls about humans in general — is a dangerous combination. Some of our other owls are frequenting airports and highways, but for sheer danger, Philly was in by far the riskiest place.”
The transmitters have provided a level of detail that most bird-tracking devices cannot. “We are currently getting 48 locations a day that are accurate to a fraction of a meter, and in 3D (latitude/longitude/altitude),” Weidensaul says. “We can zoom in with such detail that we can tell if the owl was on the south-facing slope of a beach house roof or the north-facing slope.”
Weidensaul downloads data from the transmitters into Google Earth. The purple lines below plot the movements of Assateague, the first owl tagged by the researchers, just before Christmas. The map shows Reeds Beach, New Jersey, on the shore of Delaware Bay.
You can study more maps on the project’s website.
“A couple of things have really surprised us,” Weidensaul adds. “One is the degree to which some of these owls are hunting at night over open water — Assateague has hunted almost exclusively over open bays and harbors, presumably picking off ducks and other waterbirds. We’ve also been surprised to see how some of these birds are extremely localized, remaining within a roughly square-mile area, while others are roaming hundreds of miles in a few weeks across several states. Finally, one of the coolest things to watch is how some of these owls are riding ice floes out into the Great Lakes, and hunting the edge of the ice line — again, presumably for waterbirds. This is analogous to the recently described behavior of Snowies that winter on Arctic pack ice, hunting sea ducks at open-water polynyas.”
The project has raised more than $31,000 — well more than its initial $20,000 goal. “More than half the budget has come directly from public fundraising on the Indiegogo site,” Weidensaul says. Sponsorships by state ornithological societies have contributed much of the rest.
Donations on Indiegogo will be accepted until March 1. After that, tax-deductible donations will be accepted through the Ned Smith Center for Nature and Art, a Millersburg, Pennsylvania, non-profit where Weidensaul serves as the collections curator and the coordinator of its Northern Saw-whet Owl banding program.
“While we have the transmitters fully funded,” he says, “what we need now is support to allow us to do the additional analyses and lab work — blood sexing, genetics, stable isotopes, toxicology and necropsy work on owls coming into rehab centers and found dead, and a good deal more.” — Matt Mendenhall, Managing Editor