Decade-long research project tracks snowy owls
During the winter of 2013-14, the eastern U.S. saw the largest incursion of snowy owls in nearly a century. The influx prompted an ongoing study of the birds. The Adirondack Land Trust recently hosted a webinar with one of the project’s key researchers.
The Adirondack Land Trust began the webinar with a video explaining the group’s work including preserving lands and natural habitats. Stewardship manager Derek Rogers calls himself an avid birder and says at least 212 species have been documented on lands protected by the Trust.
“One species in particular that has been found on some of our farmland properties that we’ve conserved is the highly coveted snowy owl, a bird that will even get the non-birders outside on the coldest of winter days. They’re captivating, elegant and mysterious.”
A study known as Project SNOWstorm has been tracking snowy owls for a decade. Project co-founder Scott Weidensaul says the research study came together very quickly when a large incursion of owls occurred in the winter of 2013.
“This was the biggest invasion of snowy owls into the east and central North America since at least the winter of 1926-1927 and perhaps as far back as the 1890’s,” reported Weidensaul. “And when this happened, when this wall of white birds came flooding out of Canada, the story went something like these starving hungry owls are forced south by starvation. It was not hunger and privation. In fact, you had a large number of snowy owls nesting there that produced a very large number of chicks and there was enough food that almost all of those babies survived. And it was mostly those young owls flying south the next winter on their first migration that provoked that enormous mega-irruption that we saw in the winter of 2013-2014.”
Weidensaul said the incursion led to what has been a highly successful decade-long study of the raptor.
“Project SNOWstorm has grown into certainly one of the largest snowy owl research projects in the world,” Weidensaul said. “We’ve used these GPS – GSM transmitters. We’ve deployed them on 110 snowy owls in 17 states and provinces. Since we’re going to the trouble of catching these birds anyway, we want to get as much information from them as possible. So we collect blood, feather and DNA samples. That allows us to look at the genetic structure of North America’s snowy owl population. We can look at stable chemical isotopes in their feathers, in their blood, in their tissue that can tell us for example how their diet changes over time. And it also gives us an opportunity to look at what kind of environmental toxins these birds are picking up.”
The data from the GPS transmitters is providing researchers with new information on the birds, and Weidensaul says the snowy owls provide constant unexpected information.
“Pretty much every single bird that we’ve ever put a transmitter on has surprised us in some way, starting with the very first one,” recalled Weidensaul. “It was a juvenile male and surprised us because when we started getting his data we realized this bird was not doing any hunting over land. Now this is a snowy owl and everybody knows that snowy owls eat small furry animals like lemmings. There’s not a lot of small furry animals out in the middle of the Delaware Bay. But that’s where this bird was doing all of his hunting at night out over the open water. He wasn’t hunting small mammals. He was hunting water birds. Now we’ve also have had many birds that have wintered in coastal environments like this that do all of their hunting over land. So one of the things that we have found with all of these snowy owls is that they are very individualistic.”
On January 14th, Project SNOWstorm reported two snowy owls had returned to cell range near Montreal and tracking data had been received. Weidensaul said it has been a slow winter so far tracking tagged snowy owls traveling south from the Arctic.
“There could be two things going on,” noted Weidensaul. “We have a real epidemic in North America right now with highly pathogenic avian influenza and we know that snowy owls have been affected and we suspect that a number of our tagged owls two winters ago succumbed to highly pathogenic avian influenza. So that may be part of the issue. But it’s also been an unusually warm winter across much of the Arctic and subarctic and my suspicion is that those owls are just still up there.”
All of the data from the owls is posted online but the data posting is time delayed.