Northern owls visit Outside birdwatchers
Hundreds of boreal and other owls usually seen only in the far northern forests are being spotted as far south as Minnesota, a place where glimpsing just one would usually be cause for excitement, reports Audubon's director of citizen science Paul Green at The Great Backyard Bird Count project Web site.
Audubon is a co-organizer of the Great Backyard Bird Count, Project Feederwatch, and other projects that help track bird movements and populations with the help of “citizen scientists”—volunteers who agree to count birds in their regions.
The winter of 2004-2005 is proving to be a bumper year for owls moving south, including Great Gray Owls, says a report from eBird, a joint program between Audubon and the Cornell University Laboratory of Ornithology. Experts say the massive movement of these owls appears to be part of an “invasion” that occurs about once every 10 years, in response to changes in food supply.
“Studies have shown that only a scarcity of rodents could force the Great Gray Owls from their breeding areas in the north,” writes Green. “If a drop in the vole population follows a food-rich summer in which many young owls fledged, large numbers of young birds swell the numbers of older birds that are seeking better hunting grounds.
“Several species, including Great Gray Owl, Northern Hawk Owl, and Boreal Owl, all put in early showings in Minnesota in the fall of 2004. In Minnesota this winter, reports of owls are up by more than thirty-fold over a more typical year, with more than 1,715 reports of Great Gray Owls, 300 Northern Hawk Owls, and 400 Boreal Owls reported by mid-January. This compares with last year’s more typical numbers of 35, 6, and 1 respectively.”[Read more at Great Backyard Bird Count]
| Posted 02.16.05 at 6:40 pm