I have never quite developed a deep interest in birds, although I have made intermittent attempts over the years. That said, I'm not sure I agree with a remark made by my friend David Banks a number of years ago to the effect that birders and non-birders don't mix well on wilderness trips. Just ask Taldi Walter, who knows from experience that there is nothing like my constant carping about all the bird watching to liven up the tundra conversation. Just kidding, more or less, and David is probably right that I don't really fit in with a hard-core bird watching expedition.
I was thinking recently about a trip 15 years ago that was one of my first opportunities to see a serious birder at work. We were hiking along a river valley in the western Brooks Range when Diane Okonek grew excited upon spotting a tiny dot far off in the distant sky. Barely visible, it was circling low along the sides of a cliff. “I’ll bet it’s a gyrfalcon!” she exclaimed. That meant, of course, that we had to hike over to the cliff and about half way up a steep talus slope in order to make a positive identification of the bird and find the location of its nest.
I later learned to appreciate that Diane had context for her initial observation. She knew that gyrfalcons are fairly common in northern Alaska, being one of the two species of raptors that breed exclusively at high latitudes. The other species is the rough-legged hawk. Two others, the peregrine falcon and the golden eagle, can be found in the arctic as well, but their range also extends into lower latitudes. All four species like to nest on high ledges of mountainous cliffs. So there was an excellent chance that the bird she saw would be one of these four species.
She had also noted that the far off dot was maneuvering relatively close to the ground after first being spotted up near the top of the cliff. This would be characteristic of the gyrfalcon, which hunts fast and low, plucking its prey off the ground. Diane would have known that this hunting technique differs from those of the other arctic raptors. A peregrine, for example, stoops down on its prey, typically a bird in flight, from above. Rough-legs and eagles tend to soar high in the sky, not hunt across the tundra close to the ground as a gyrfalcon does.
I did not know any of this at the time, of course, but later gleaned most of it from E.C. Pielou’s A Naturalist’s Guide to the Arctic. Reading up on arctic raptors, I thought back to that long ago day in the Kobuk drainage and I suddenly realized the elements of Diane's identification process. She must have previously internalized this knowledge and used it almost without conscious reflection to make an educated guess as to the bird’s identity when she first spotted it in the distance.
Hiking over to the cliff cannot really be described as a detour because we had no particular path to follow and we had all the time afforded by a long arctic day to not follow it. Eventually we were able to get a better look at the bird and its mate through our binoculars, their tapered silhouettes further ruling out the rough-leg and the eagle as candidates. And, of course, patient scanning and observation eventually revealed the nest, high up on the crest of the tall cliff.
I am intrigued that birders work through this logical progression, often without being conscious of its intellectual rigor, starting with a framework of contextual knowledge about habitat and the various species that could potentially be present. They incorporate what they know about avian behavior into the model, in this case the hunting pattern of the gyrfalcon, which would contrast with the other candidate species. And then they progress to specific observation of shape, plumage and the like, and, when possible, of the audible cries of the animal.
Maybe I will carp a little less next time. Or not.
Saturday: Happy birthday to North of Hope.
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