Here in California, out of hunting season, danger for most birds comes primarily from above. Hawks and falcons pose the most danger for adult birds. When I process many of my images I see the birds looking up; I assume they are on the look out for danger coming at them from above. This Green-winged Teal definitely fit this picture. Shortly after this image was taken a Red-winged Hawk floated over the pond. A RWH is not much of a danger to an adult teal, but none the less, all the ducks exploded into flight; the hawk floated away and back the ducks came.
Taken with a R7, hand held with the lens just above the water; processed in PS with healthy crop. BG brought down slightly and shadows on bird brought up slightly.