Tracking Snowy Owls

With cutting-edge tracking technology, we can follow the movements of snowy owls in astounding detail, and potentially for years at a time. But we need your help to quickly raise funds to purchase additional transmitters.

Collaborating scientists in Project SNOWstorm are tagging owls throughout the Northeast and Great Lakes with new GPS-GSM transmitters made by Cellular Tracking Technologies of Somerset, PA.

How they work

These solar-powered transmitters record locations in three dimensions (latitude, longitude and altitude) at programmable intervals as short as every 30 seconds, providing unmatched detail on the movements of these birds, 24 hours a day.

Unlike conventional transmitters, which report their data via Argos satellites in orbit, GSM transmitters use the cellular phone network. When the bird is out of range of a cell tower, the transmitters can store up to 100,000 locations, then transmit that information — even years later — when the bird flies within cell coverage.

The transmitters weigh about 40 grams — about as much as seven U.S. quarters, and only 1.5-3 percent of the bird’s weight. They are attached with a backpack harness made of low-friction Teflon ribbon that goes over the bird’s wings. Studies of snowy owls wearing conventional satellite transmitters in this fashion have found no evidence that they increase mortality or decrease breeding success (Therrien et al. 2012).

Still, we’re careful only to tag snowy owls that are in robust health. As experienced researchers, we assess every owl we catch to make sure it is in good shape, with normal weight and healthy fat stores. Any owl that seems questionable will not be tagged.

What will we learn? Almost nothing is known about the local and landscape-level movements of snowy owls on the wintering grounds, nor about their nocturnal hunting activity and range size.

Following the first owls

The very first owl we tagged provided some big surprises. Caught on Assateague Island in Maryland on Dec. 17, “Assateague” left two days later and flew north, loafing for a day on Cape Henlopen, Delaware, then crossing 38 miles of open water to reach the north shore of Delaware Bay. Then he moved down the New Jersey coast to the village of Reed’s Beach, where he spent a week. See Figure 1.

Leaving Reed’s Beach, he flew across southern New Jersey in the middle of the night, following the Tuckahoe River to the coast, then flying up the tightly-packed coastal towns to Atlantic City. Stopping briefly on the famous Steel Pier, he continued up the coast to the town of Brigantine, almost 100 straight-line miles (and more than 150 flying miles) from where he’d started just 11 days earlier. See Figure 2.

By contrast, a snowy owl tagged Dec. 23 in central Wisconsin has rarely roamed more than a mile from where it was caught, in the Buena Vista grasslands of Portage County. Project SNOWstorm is showing how different owls respond to different conditions. See Figure 3.

Our goal

It is our goal to use GPS tags on snowy owls across the 2013-14 irruption zone, from Minnesota to New England. But to do that, we’ll need your help. The transmitters are roughly $3,000 each, and while we’ve received seed money to pay for the first few, we need the public’s help to purchase the units we need. Any amount will help, and donations are tax-deductible through the Ned Smith Center for Nature and Art, a 501(c)3 nonprofit.

Donate today!


Therrien, J-F., G. Gauthier and J. Bêty. 2012. Survival and reproduction of adult snowy owls tracked by satellite. Journal of Wildlife Management 76(8):1562-1567.