Duck: It's what's for dinner

Along Interstate 80 in the central Platte River Valley of Nebraska are numerous ponds that originated as borrow pits during the highway's construction. Jessa and I stopped to take pictures at one such near the town of Hershey last weekend. Most of the pit ponds were frozen over, but this one had been kept partially open by bird activity. At one end of the pond were the engineers of the opening, a flock of mallards with a few gadwall, widgeon, and cackling geese (mini-Canadas) mixed in.

And in the other corner...

Actually, the pond was nigh infested (from the ducks' point of view) with bald eagles of all ages; there was a fair bit of coming and going that made an exact count problematic, but we estimated a total of fifteen eagles present at any given moment: on the ice, in the air, or perched in the trees that ringed the pond.

Most of the activity centered on the ice near the eastern extent of the open water, where a duck carcass was squabbled over and changed hands several times. 

We didn't see the kill—it had happened well before our arrival—but I'm pretty sure I can describe how it happened. Any time one of the eagles gathered on the ice took off, flying low over the pond to take a perch in the cottonwoods—or anytime the reverse happened, with an eagle gliding down to take part in the melée—pandemonium ensued amongst the ducks. Not all of the ducks—most of the flock remained alert but calm—but those in the immediate vicinity of the low-flying eagle scrambled all over each other trying to get out of the way, lest the raptor reach down with a taloned foot and snatch one of their number into another plane of existence. But in my mind's eye, that's not how it went down.

While the eagles on the pond casually, perhaps even innocently, kept the ducks wary of daylight kidnap/murder, another eagle making a long, flat stoop from a half-mile away was suddenly in their midst, with a mallard dead on the ice almost before its compatriots realised they were under attack. My guess is that this happens a couple of times a day, and how are the ducks to plan a defense?

But perhaps they get plucked from the pond by casual, low-flying eagles as well.

In truth, none of the eagles, even the young birds, seemed desperately hungry, and at times the carcass was in no one's actual possession—further evidence that the pond was in a state of equilibrium: the eagles (the adult eagles, at any rate) catching ducks basically at will, and the ducks numerous enough to sustain these losses without feeling pressured enough to depart.

Eventually, one of the young eagles carried what was left of the duck to a tree, prompting more brief squabbling but soon thereafter putting an end to the eagle show, or at least bringing it to an intermission.

We had a concert ahead of us and many miles left to go, so Jessa and I reluctantly left the pond...but the eagles seemed to have things well under control.