Posed

Another shot of the beautiful Great Gray Owl that some of us saw at Griffith Woods, in hunting mode. I was lucky enough to see it on 10 January 2014 and again in February. Normally, we don't get Great Gray Owls in Calgary, so this was such a treat. I haven't seen or heard any reports or photos of it since then, so maybe it has moved on.

A few days after I saw the owl, friend Bonnie sent me the following information that she had received from Gus Yaki, a well-known Naturalist in the city. This owl hadn't been seen for three days, so maybe it had moved on. When asked about the possibility of the food supply having run out, he did not think the owl was feeding well because it was hunting during mid-day. It should have been hunting at dawn and dusk and sleeping during the day. He said they have excellent hearing. Also, he said he has not seen many small mammal tracks at this location and apparently the Meadow Voles have to surface to allow carbon dioxide to exit from their tunnels. He also said the owls see in ultraviolet which causes mouse urine to shine so they would see that.

"These birds wait, listen, and watch for prey, then swoop down; they also may fly low through open areas in search of prey. Their large facial disks, also known as "ruffs", focus sound, and the asymmetrical placement of their ears assists them in locating prey, because of the lack of light during the late and early hours in which they hunt. On the nesting grounds, they mainly hunt at night and near dawn and dusk; at other times, they are active mostly during the night.

They have excellent hearing, and may locate (and then capture) prey moving beneath 60 cm (2.0 ft) of snow in a series of tunnels solely with that sense. They then can crash to a snow depth roughly equal to their own body size to grab their prey. Only this species and, more infrequently, other fairly large owls from the Strix genus are known to "snow-plunge" for prey, a habit that is thought to require superb hearing not possessed by all types of owls." From Wikipedia.

The first link shows a cross-section of a Great Gray Owl, showing the small size of the skeleton compared to the bulk of the plumage:

upload.wikimedia.org/wikipedia/commons/thumb/4/40/Strix_n...

en.wikipedia.org/wiki/Great_Grey_Owl

www.flickr.com/photos/annkelliott/13311735493