Wednesday, 19 July 2017

Powerful Owl portraits

The Powerful Owl (Ninox strenua) is Australia’s largest owl with the Rufous Owl (Ninox rufa) coming a very close second in size. Now and again Powerful Owls can be found perched in a day-time roost in a shady tree and often they are clutching prey taken the night before.  

Please click on photos to enlarge.

Powerful Owl at a typical day time roost- a bare near-horizontal branch close to the trunk of the tree for perching and a Boobialla tree providing screening and shade.

Powerful Owls will often allow reasonably close approach when found in day-time roosts however they will flush if approached too closely, which I have done inadvertently on a couple of occasions.

The following portraits and cropped detailed shots were taken of the owl in the above photo using a 500mm prime lens which required the camera to be a good distance from the owl in order to fit the subject into the (full frame) camera frame.

The classic full frontal Powerful Owl portrait with piercing yellow/orange eyes instantly drawing our attention. The pupils are partly dilated in the shady roost location.

Unlike human eyes that swivel in their sockets owl eyes are fixed, so to look at something directly, owls must move their heads and face the object of their attention.

This head side-on photo was possible because the owl is looking to its right at another photographer.
Close to a full side-on head profile which shows the rictal bristles well. The sharply pointed hooked bill used for ripping flesh is also apparent.

Many bird species have rictal bristles including owls. However the purpose of these bristles is not clear. One function proposed for these bristles is sensory. For nocturnal birds such as owls, the bristles may help detect sound. My thought is the bristles may help protect the eyes. For a night flying bird the risk of hitting something like fine leaves is high and the consequences of eye damage is serious so perhaps the rictal bristles when encountering any foreign object cause the eyes to automatically close. This of course is pure speculation on my part.

The following photo is a cropped detail showing the feet and talons of the bird’s left foot on which it is perched – the other foot is tucked up almost out of sight under the belly feathers.

Only two of the bird’s four toes are visible with the other two obviously facing backwards. When in flight and sometimes when perching, three toes are held forward. Mostly when perching and when clutching prey the outer toe swivels backwards leaving only two toes facing forward. Also visible in the cropped foot detail are the long sharp lethal talons and the rough textured soles of the feet which helps the bird grasp prey. The feet are yellow however I am sure there are traces of blood visible on the feet.

You can find more on owl physiology here:

Once the two other photographers left the owl looked steadfastly straight ahead. Fortunately for me this was in the only direction that allowed a clear view of the bird.

For most birds their facial expressions are fairly fixed however owls with their forward-facing eyes can show a surprising variety of expressions, for example the wise-owl look. However the expressions we see are our own anthropocentric creations and should not be used to read anything into how the bird is feeling or what is it thinking. That said here are a few portraits showing various facial poses.  

Of course, being daytime it was the owl’s sleep time so as I stood quietly the owl’s eyes began to droop indicating the owl was not too troubled by my presence.

Each time I took a photo the owl’s eyes opened when it heard the camera shutter release. My camera clock indicated I had been with the bird for about 20 minutes, it was time to leave it in peace, so I departed, thankful for the opportunity to take some photos of the magnificent Powerful Owl.

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