It was late in the afternoon and not much seemed to be happening in the mud flats east of the park. Then my eyes caught a green flash, on and off and on again. I fired up the telephoto lens and there it was: the neck of a male Mallard, dabbling in the mud. This was an energetic bird, stirring up the bottom of the tidal puddles, to the point where mud dulled its iridescent green up above the eyes. Eventually the sun dipped and the shade moved up and the bird’s flash dimmed, and I moved on. The next morning at 8, at the same spot up on the bank, what did I see? Sitting as calm as could be, as if it owned the place, the same drake — at least I’m assuming it was the same bird. It had its head tucked into its wing on the far side from me. They say a duck never sleeps, and this one lived up to that saying. As I approached and set up my camera, the bird raised its head and had a good long side view of me. Then it decided I wasn’t a threat, tucked its head back into its wing, and continued its morning nap.
There’s science behind the saying that “ducks never sleep.” At least, halfway. Ducks have evolved the ability to sleep with half their brain while the other half remains alert and functional. Typically they’ll keep an open eye toward the side where danger might approach, and keep the other eye closed. Source. This particular Mallard, however, felt so safe that it kept both eyes shut. But very likely, it kept one ear open. That’s how it knew a photographer had approached.