Back in December, I described an invasion of snowy owls from the arctic to temperate latitudes. Hundreds of these impressive white birds have been reported from the east coast to Minnesota. I suspect that never have so many birders seen a rare life bird in such a short time span.
Similar habitats
Because snowy owls normally live on the open spaces of the arctic tundra, they seek similar habitats when these irruptions occur. Many end up finding abundant rodent populations at airports, farmlands, and even urban parking lots. Airports can be a problem because aircraft can hit and kill snowy owls, but more importantly a single owl can take down a plane. So as these owls arrived in bigger numbers, conservationists have worked to capture and relocate snowy owls away from airports so they would not have to be killed to keep airports safe.
Once in a lifetime
Conservationists also realized that snowy owl irruptions of this magnitude can be once in a lifetime events, so a team of experienced owl researchers quickly assembled to capture, tag, and monitor as many snowy owls as possible. Thus Project SNOWstorm was born. Using telemetry, banding, and other biological research tools, biologists are hoping to unravel many of the mysteries that surround the biology of snowy owls.
Leading Project SNOWstorm are David Brinker, a biologist with the Maryland Department of Natural Resources, Scott Weidensaul, an owl biologist with the Ned Smith Center for Nature and Art in Pennsylvania, and Norman Smith from Massachusetts Audubon, who has been studying snowy owls for more than 30 years at Boston’s Logan Airport.
“The basic structure of the whole project, …” Brinker explained, “came together in about 10 days.”
Expensive job
Capturing and equipping owls with telemetry devices and then monitoring them are time consuming, expensive jobs. Each transmitter costs about $3,000. But thanks to the generosity of people from around the world, the project raised more than $20,000 in about two weeks. Though most of the donations came from the U.S., several contributions came from as far away as the U.K. and Italy, according to Weidensaul.
The first snowy owl equipped with a transmitter was trapped on Assateague Island National Seashore in Maryland on December 17th. A second owl was outfitted with a transmitter on December 23rd in Wisconsin on the Buena Vista Grasslands. The team named these birds “Assateague” and
“Buena Vista” to note the locations where they were captured.
Owls with transmitters
Since then, “Philly” was trapped and tagged at the Philadelphia International Airport and “Erie” and “Millcreek” were tagged near Erie, Pa., bringing the total number of owls fitted with transmitters to five.
Meanwhile many more snowy owls have been captured and banded in many states. Most of these birds are healthy. The notion that snowy owls irrupt south in winter to avoid starvation is a myth. More likely these irruptions are spawned by spectacular nesting success the previous breeding season.
Snowy owls lay more eggs, as many as 13, when lemmings are abundant, and last year was a banner year for lemmings. So younger birds head south after an unusually successful breeding season to escape competition for food with adults.
Prey availability
Though only a few owls have been fitted with transmitter so far, we have already learned a lot. “Assateague,” for example, moved 150 miles to various spots along the New Jersey shore where a variety of prey are available.
“Philly” was relocated 40 miles west of the Philadelphia airport to the farmland of Lancaster County. But three days later, Philly returned to the airport. If nothing else, this is an amazing example of avian homing and navigation. Weidensaul says, “By tracking transmitter locations, we watched as it followed the turnpike back to the airport.”
Though snowy owls eat primarily lemmings during the nesting season, when they winter this far south, their menu options expand. Reports from the hundreds of observations that birders have submitted include snowy owls eating a variety of waterfowl, coots, and gulls.
Follow the story
To follow the snowy owl story as it unfolds, visit www.projectsnowstorm.org. To help support the research, tax-deductible contributions can be sent to the “Ned Smith Center for Nature and Art,” 176 Water Company Road, Mechanicsburg, PA 17061; note “Project SNOWstorm” on the check.
