Great Gray Owl hunting

On 10 February 2014, I returned to Griffith Woods, where I had been lucky enough to see a Great Gray Owl on 10 January 2014. As I walked into the area, I could see a large, dark object sitting on the top of a very tall tree. During the time I was there, the owl plunged twice into the deep snow and caught a Meadow Vole, as well as flying to several different trees. Great Gray Owls are not normally seen in Calgary, so this was a real treat.

"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