Owls on the move

Owls of the north, like this Great Grey, flocked en masse to Minnesota last winter. The rare winter irruption occurs when food is sparse in their natural habitats.

Photos courtesy of The Raptor Center; homepage photo by Patrick O'Leary

March 3, 2006

Last winter, hotels and restaurants across northern Minnesota were filled with excited, binocular-toting visitors from California to New York. They were drawn to Minnesota in frigid January to witness first-hand the rare event of an owl irruption.

Owl irruptions or invasions occur during cyclic lows in the owls' prey populations (voles, lemmings, and other small rodents) in the owls' normal winter habitat, which includes much of Canada and northern Minnesota. During these low points, which occur every 7 to 12 years, the owls are forced south from their usual habitat in search of food. In early 2005, northern Minnesota trees were "dripping with owls," as more than 5,000 owls made Minnesota home.

Bird researchers didn't waste time in gathering data on this irruption, and now it's time to share what they've learned.

The symposium, "Owls On The Move: When, Where and Why," will be held the weekend of March 17 to 19 at the University of Minnesota, Duluth (UMD). The UMD Natural Resources Research Institute (NRRI) is one of the major sponsors, as is the UMD biology department and The Raptor Center on the Twin Cities campus in St. Paul.

Raptor Center to the rescue

An unusually large number of the owls that invaded northern Minnesota in winter 2004-05 ended up in The Raptor Center at the University of Minnesota.

"Although this southern movement is normal in years when the owls' food sources are scarce up north, an invasion brings them in closer contact with humans, often to the owls' disadvantage," says Julia Ponder, a Raptor Center veterinarian. "Many of these birds are hit by cars or suffer other traumatic injury."

The center admitted 116 owls--great gray owls and northern hawk owls. The owls received treatments ranging from supportive medical care to advanced orthopedic surgery. In winter 1995-96, the center treated 15 great gray owls, most from the Twin Cities area. However, in a typical year, the center sees only one or two of these elusive birds.

On Friday evening, a family-focused Northern Owl Fair featuring live owls, storytellers, music, art, owl callers, and games will kick off the symposium. Saturday will see speakers from around the globe, including NRRI scientists Jim Lind and Dave Grosshuesch, discussing owl habits and past irruptions in Minnesota and across the United States and Canada. Keynote speaker, Pertti Saurola, will give some insight on owls in Finland. At a banquet that night, local author and photographer Mike Furtman will showcase images from the recent irruption. On Sunday, Raptor Center experts will participate in discussion groups and workshops. Topics include ecotourism, the future of owls and owl research, photography, educating with owls, wildlife rehabilitation, and volunteer opportunities.

Raptor Center vets treated more than 30 great gray owls during the recent irruption.

Tickets for the symposium are $60; banquet tickets are $20 per person. You can attend the Northern Owl Fair without registering for the symposium; fair tickets are $2 per person ($6 maximum per family).

For complete information about the symposium, including speakers and their presentation topics, and to register online, visit the Hawk Ridge Bird Observatory.