Tag Archives: Forest Under Story

… I came to see the owls as one of countless shapes the forest assumes, more than as an animal that resides in a forest. In this view, if the organism is removed from the old growth, it ceases to be a spotted owl and becomes just a brown, speckled, dark-eyed, meat-eating bird.

The feature that most exemplifies this awareness for me is the owl’s feathers. Unlike most raptors in this region, northern spotted owls don’t migrate south in the winter. They are here in rain and snow and cold. Yet they are not exceptional thermoregulators as one would expect of a nonmigrant facing a rainy, snowy Cascade Mountain winter.

The reason for this counterintuitive disparity is the old-growth forest, which buffers temperature extremes at both ends of the spectrum by as much as twenty degrees Fahrenheit in relation to adjacent clearings. The owls wear old growth like another layer of feathers. That is, their preferred habitat provides sufficient thermal protection, so that they do not have to expend energy growing as much down as they would need if they dwelled in open country.

The deep multilayered canopy characteristic of old-growth groves also intercepts enough snow to permit the owl’s preferred prey species – the northern flying squirrel – to remain active all winter long, feeding on truffle mushrooms on the open ground at the bottom of snow wells around the bases of the trees. With food and warmth (as well as many other life needs) literally covered by the old growth, the owl does not have to make a long flight to warmer climes at the onset of autumn.

Instead, the owl makes short flights in response to immediate conditions. Sun gaps on otherwise snowy January days draw them out from beneath sheltering midcanopy mistletoe umbrellas to ascend to high branches, where direct solar radiance can offer springlike warmth even during the coldest time of year. And in the heat of August, the owls are often found perched low in vine maples a few feet above a cooling creek in shady northeast- facing drainages. This behavioural thermoregulation and the incorporation of the forest itself into their meaningful physiology provide just two of many possible examples that demonstrate why efforts to reduce the spotted owl to a bird in a habitat represents extreme oversimplification.

from The Mountain Lion by Tim Fox, excerpted in Forest Under Story

Where does the forest end and the owl begin?

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