Naturalist’s Notebook: Mallard Commotion

17 February 2008
Isabella Reservoir’s North Fork Delta
Kern River Valley, California

This morning’s tranquil bird walk abruptly gave way to an intense drama. A frenzied eruption of gulls and ducks exploding from the flooded weedy flats drew my attention to an adult Peregrine Falcon battling to subdue a wildly struggling female Mallard. A pause in the duck’s violent flapping and lunging finally allowed the big falcon to deliver killing bites to its neck. After a minute or two, the duck ceased its struggles, and the falcon began plucking out large clumps of feathers.

A moment later, an immature Bald Eagle came into view, flushing clouds of gulls and ducks in its path as it flew fast and low toward the feeding peregrine. But the falcon saw the approaching eagle and launched from the ground to intercept it, executing a rapid sequence of vicious stoops, diving at the larger bird again and again to keep it away from its kill. The eagle had to swerve evasively and do a half roll, presenting its talons to fend off the screaming falcon’s determined stoops. But Bald Eagles are hard-wired thieves, and it took more than an attacking Peregrine Falcon to deter it from this easy food. The eagle quickly took advantage of a pause in the peregrine’s attacks (caused by some harassing Common Ravens that had joined the melee) and swooped down to seize the duck carcass.

The big brown-and-white eagle’s victory, however, was short-lived; within a couple of minutes, two more Bald Eagles came sprinting in, circling low above the young eagle as it mantled over the duck. The new arrivals soon landed near the kill, and the scene quickly devolved into the inevitable tug-of-war for the carcass between the three eagles. With a lot of wing-flaring, heavy-bodied lunging, and lashing out with rapier talons, possession of the duck changed many times. In the span of an hour, the duck was reduced to scraps, each eagle with its own morsel. Dozens of ravens were there, too, searching for overlooked morsels on the fringes. A couple of ravens even dared to attempt distracting an eagle from its meal by sneaking up behind it and tugging on its wing or tail. All the while, the Peregrine Falcon looked on from a tall gray pine on the hillside.