Date: 12/6/17 6:37 am From: Emily Weiser <emily.l.weiser...> Subject: [wisb] Re: 5 Snowy Owls Near La Crosse
Wow! Thanks for the report. The Birds of North America account (updated in 2015) says the following about sociality in Snowy Owls:
"Not fully understood. On breeding grounds adults maintains exclusive territories. However, younger non-breeding adults, particularly males, often concentrate in loose groups away from territorial adults (Pitelka 1955b, DWH). Also, previously believed to be solitary and maintain individual territories outside the breeding season, with few exceptions (Parmelee 1992, see Territoriality). However, a recent study suggested Snowy Owls do form communal roosts in winter and may be highly social (see Holt and Zetteberg 2008)."
The last reference is:
Holt, D. W. and S. A. Zetterberg. 2008. The 2005 to 2006 Snowy Owl irruption migration to western Montana. Northwestern Naturalist 89 (3):145-151.
(but a membership is required to read the BNA account quoted above).
So, there is apparently no information about relatedness of birds that are spatially clustered. If nonbreeding males tend to group together, and if many birds that winter here are in their first year, I would speculate that perhaps the groups are not necessarily familial.
On Wed, Dec 6, 2017 at 8:06 AM, Dan Jackson <DanJackson...> wrote:
> On Monday morning, the refuge manager for the La Crosse District of the > Upper Mississippi National Fish and Wildlife Refuge spotted an immature > female Snowy Owl at the refuge Visitor Center on Brice Prairie (west of > Onalaska off of County ZN. By late afternoon, 2 more had been seen. > > > > Yesterday, three birds were perched in the parking lot of the maintenance > building at dawn. When refuge employees picked up equipment for the day’s > projects, the birds spooked and flew into the corn field just to the north. > > > > At dusk, while a few of us were watching those 3 birds, we were surprised > to see 2 other birds fly by making a total of 5. At least 2 were immature > females and 2 were lightly barred and were either immature males or adult > females. > > > > The birds got active between 4:30 and dark and moved up from their perches > on the ground to perch on signs, posts, tractors, telephone poles, and > other vantage points – making them easier to see. > > > > Someone asked if they might migrate as family groups and could these birds > be related? Has anyone done genetic testing of groups of birds found at a > single location before (Duluth Airport, etc.)? > > > > Good Birding, > > > > Dan Jackson > > Chaseburg, Vernon County, Wisconsin (Near La Crosse) > > www.PBase.com/DEJackson > > > > >