he great gray owl is a large bird – the longest owl in the world – but not the heaviest. Adults are 24-33 inches long with a five-foot-long wingspan. They have a noticeably rounded face and yellow eyes. Their thick feathers make them appear much larger than their body – in general, the more common great horned owl weighs about 15% more than the great gray. Male great grays will weigh up to 2.2 lbs while females will weigh up to 2.8 lbs. Female owls and other raptors typically weigh about a third more than the male (thus male raptors are referred to as tiercels – from a third – also said to have been derived from the belief that only every third egg would produce a male). The ecological reason as to why females weigh more than males has been in debate for some time and ranges from the smaller agile males ability to catch smaller prey to the energetic costs of producing a full clutch of eggs. Believe me – this could go on for pages.
These are birds of the north woods and the range across Canada and dip into the north woods of Minnesota and Michigan, and into the Cascades and Rocky Mountains and into Wyoming, with some isolated populations in southern Oregon and in the California Sierra Nevada. It can wander further south from Canada during times of prey scarcity.
Nebulosa means misty or foggy – this bird also is known as the gray ghost and phantom of the north because it is not commonly encountered. In Europe they are found in Norway and Sweden and are more numerous in Finland and across Russia. They tend not to migrate and will inhabit their territory year-round.
These owls hunt during the day from a perch site, watching and listening for small mammals. The genus Strix are the owls without ear tuffs – they do have ears, just no visible features. But – the contours of their face feathers funnel the sound to their ears, like a feathered satellite dish. They have very acute hearing and can sense small mammals under the snow at 100 yards away. Thus, they will hunt without seeing their quarry, catching prey beneath the snow.
This activity, known as a snow-plunge, is exhibited by great grays and a few other owls in the genus Strix with exceptional hearing. They will eat a variety of rodents and animals up to the size of a snowshoe hare and the occasional bird. Here’s a short video explaining the snow-plunge behavior: http://www.youtube.com/watch?v=o2GNHxlEnXg&feature=player_embedded
They are found in boreal forests and hunt in open areas. They don’t build their own nests but will take over a previously constructed raptor nest or set up house in the trunk of a broken top tree. The male will prepare for breeding by conducting aerial displays and bring prey gifts to the female. You know – the usual dating behavior. An average of 4 eggs is laid with an incubation period of about 30 days. Because of their size great grays have few predators but bears, goshawks, small carnivores, and other owls will prey on the nestlings.
The first photo was taken along the George Parks Highway between Fairbanks and Denali National Park. I’d been working up around Fairbanks and tacked on a weekend trip to Denali and was zipping down the road (of course looking for critters) when I spotted this guy. So I turned around and parked and watched him watch me for about 15 minutes. He seemed more bored than me, but didn’t fly away.
I do wish it would have done this though, but I didn’t have a mouse at hand: http://www.youtube.com/watch?v=G_KZiC2z71I