[dropcap letter=”D”]riving through Maine, you sooner or later pass under high-tension wires. On either side of the road, big clear-cut corridors — the interstate highways of the power grid — stretch over hill and dale, highway and river, carrying the electricity that keeps us humming. On the pylons that hold the wires aloft, you occasionally see an osprey nest — a shabby mess of sticks and twigs, compared to which a rat’s nest is a Grecian Urn.
Ospreys antedate homo sapiens by many thousand millennia.
Like us, they inhabit every continent and subcontinent except Antarctica. Unlike us, they are antisocial specialists. They catch fish in shallow water. It’s always worked for them. But 50 years ago, they seemed destined for oblivion. Then, in 1972, the EPA outlawed the lethal pesticides that had drastically reduced ospreys’ reproductive success, and the Clean Rivers Act became law, reviving the fisheries in many rivers and bays that the birds depended on. The population rebounded with surprising speed and vigor. Which caused a new problem: a shortage of suitable nesting sites along our highly developed waterfronts.
The birds solved this one themselves. They nested on bridge girders, navigational buoys, pilings, piers, and transmission towers. As for us, they tolerated our proximity but did not look for handouts. They raised their young, and then, although monogamous and the best of parents, resumed their solitary lives — migrating down to South America alone, overwintering alone, returning to their nests alone the next spring. And fishing, fishing, fishing, all the way there and all the way back.
A CMP power corridor forms the southern boundary of our property. Early last April, a pair of ospreys — newlyweds, so to speak — built themselves a nest there. Every so often, we’d see one or the other of them flying over the yard, trailing a 2- or 3-foot stick behind it, like a kite’s tail. I’d walk over to the corridor from time to time and check on their progress.
I expected the wind to make short work of the nest. But it didn’t, and I eventually saw why.
The structure they’d chosen consisted of three uprights of laminated wood, standing in a row, like goalposts set 70 feet apart, with an additional goalpost halfway between them. Two parallel timbers, bolted to each other through the tops of the uprights, constituted the crossbar. Each timber looked to be about 6 inches square — an inch or two wider than a gymnast’s balance beam. The gap between them was a little wider than they were.
The tops of the beams, where the nest was materializing, were, I reckoned, 80 feet above the ground. The view from there would be terrific; so would the wind. The “nest” that took shape was simply a thin mat of sticks, laid haphazardly across the beams and the gap between them. I expected the wind to make short work of it.
But it didn’t, and I eventually saw why. Besides the throughbolts that held the crossbars to the uprights, there were two pairs of heavy bolts across the gaps between the cross beams — to stiffen the whole structure, I suppose. The bolts were set several inches below the tops of the beams. The nest was centered over one of these pairs of bolts — they were, in effect, its floor joists, creating something between a cellar and a foundation for the center of the nest, which was built up from it to spread out over the beams.
Standing under their nest, looking down the power corridor through my binoculars, I could see an older osprey nest on the far side of the river. It was in the identical place, on an upright-and-crossbeam arrangement identical to the one over my head: about a third of the way between an outer post and the center one. If I were young, I’d study this matter, study every type of pylon that had an osprey nest in it, and study the architecture of every nest. As it is, I’ll just have to think about it.