AMES, Iowa — Birders around Iowa are being treated to a rare gift this year, an inundation of Snowy Owls from the tundra! “Of course, movement of the birds into the lower 48 isn’t such a treat for them,” said Rebecca Christoffel, Iowa State University Extension wildlife specialist. “It signals trouble for them.”
Snowy Owls are large birds, with bright white plumage flecked with black and beautiful yellow eyes. Individuals stand 20 to 27 inches tall and typically perch on haystacks, fence posts and knolls or dunes. “Like our local owls, Snowy Owls are meat-eating birds, but on the tundra, their main food source is lemmings," Christoffel said, “while in Iowa, most prey items consist of mice and other small mammals.” Unlike most owls, Snowy Owls often hunt by day as well as at night.
Snowy Owls began arriving in the upper Midwest in October and have continued to increase in number as the season has progressed. Most movements of this sort, called irruptions, are thought to be caused by a crash in important prey populations; lemmings in this case. Under these conditions, younger, more inexperienced birds are forced to move south. To keep track of Snowy Owl sightings in the U.S., go to http://ebird.org/ebird/map/snoowl1.
“If you see what looks to be a large, white bucket standing in a field, get out the binoculars and take a closer look – you may be seeing a Snowy Owl,” Christoffel said. “More than 40 Snowy Owls have been reported in Iowa to date." The homepage of the Iowa Ornithologists’ Union’s website, http://www.iowabirds.org, has a map of Snowy Owl sightings. To date, six mortalities have been reported due to starvation or roadkill.
Christoffel recommends Iowans fortunate enough to see Snowy Owls report sightings to Steve Dinsmore of ISU Department of Natural Resource Ecology and Management at firstname.lastname@example.org so their movement can be adequately tracked this year.
PHOTO: Snowy Owl sited in Story County Dec. 18. Photo by Ann Johnson, Iowa Ornithologists' Union.