Friday, April 5, 2013

A Near Score of Eagles

I had a couple of good days last week, days spent in a helicopter searching for nests of Golden Eagles (Aquila chrysaetos) in eastern Oregon (and a sliver of western Idaho). Such a search involves examining every rock and tree that could harbor the large stick nests that these eagles build; mostly, it means flying past and looking closely at a whole lot of rimrock and cliffs. The flights were timed to find females incubating eggs, in which situation they are very unlikely to fly, preferring instead to remain hunkered down and unmoving. (I'll fly again in late May or early June to determine the outcome at the nests found active last week.)

Along with the pilot--Paul McIlvain--I saw a good variety of wildlife. This included Mule Deer, Pronghorn, Bighorn Sheep, and Elk. The spike bulls and some of the 4- and 5-point Elk still carried their antlers, but the largest bulls had just dropped theirs. We saw a Raccoon sleeping in an abandoned hawk nest in the top of a Cottonwood tree, and we saw a huge black bear (on the Idaho side), one of the brown ones that make up about 30% of the Idaho population but which are much rarer in Oregon. We also watched a surprised Bobcat frantically seeking cover among the boulders at the base of a rimrock. (Cats are notoriously difficult to see from the air, as they generally find sufficient shelter at the first sign of an approaching helicopter.)

As for eagles, we found 19 active nests in the area we surveyed, an excellent total for a rather moderate and unassuming area of land. Some were associated with the Snake River and the abundant variety of potential prey that inhabits the area around such a watercourse. Others were in drier country where the only obvious prey base is Chuckar and Hungarian Partridge, both of which are introduced (non-native, and thus not historically-available) game bird species. Most of the eagle nests were on rimrocks or other large cliffs, but some were on smaller exposed rock outcroppings; one was on the wall of an old quarry, and one was in a Ponderosa Pine.

It's rough work, but somebody has to do it. (See if you can find the nest and eagle in the photograph below.)

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