Friday, March 19, 2010

Boreal Owl portrait

The Boreal Owl, a.k.a Tengmalm’s Owl, is one of the most secretive residents of the boreal forest and always a real thrill to see. When a species has a different name in British and American English like this it is often a clue that the bird has a Holarctic distribution, as is the case with this species, found in both the Nearctic and Palearctic realms.

About a month ago, I had the good fortune to photograph this Boreal Owl in southeastern Manitoba, Canada. This generous individual posed for a beautiful portrait while sitting in a Jack Pine in the afternoon light – irresistible!

This next shot is a crop of the bird’s face as they hunt. The intent expression may make you think the bird is looking at something but actually they are listening to something under the snow. If you study this photo you can see the stiff dark feathers of the facial disk that help focus sound to the asymmetrical ears… below the photo I add a scan of a drawing from Owls of The World by Claus König, Friedhelm Weick, and Jan-Hendrik Becking that shows the asymmetrical ears. The different position of the ears means that sounds arrive in one ear a fraction of a second earlier than the other. The shape of the face with the stiff feathers of the facial disk focusing the sound towards the ears (much like the operation of a satellite dish) and the separation of the face into two halves helps with enhancing these subtle differences in perception. These adaptations result is hearing so precise that these owls can hunt prey they cannot see, for example they will plunge into the snow and come up with a vole than was moving in their tunnel, heard but unseen to the owl. Often when owls appear to be turning their head and looking down, they are adjusting the position of their “sound receptor”, i.e. their face, to help pinpoint a prey item before making the plunge. In the last post, I mentioned other adaptations in the wing feathers that allow them to fly quietly so that they can use their powerful hearing while hovering over a source of sound…

This owl was hunting near a feeder. Sometimes near the end of winter Boreal Owls seem to come out of the boreal forest for foraging opportunities. In this case, fallen seed under the feeder meant an opportunity for this owl. Evidence from Scandinavia suggests that males stick closer to their breeding territories whereas female disperse further to help them survive the winter – a strategy sometimes referred to as partial migration. This photo shows the owl preening at dusk, getting ready to hunt!

This last shot shows the owl flying off the feeder. It also shows my fallibility – although I was trying hard to get some flight shots, I missed the focus on this occasion. I might have to wait quite a while before another such opportunity comes my way!

Larger version of the first photo at:

1 comment:

  1. You certainly had a cooperative subject.I love the first shot.I smile as I see that not every picture is perfect,makes me feel better.I still have FAR to go in my photography skills,before I reach your expertise.


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