Photo by Chuck Homler d/b/a Focus on Wildlife
As the photo above (by Chuck Homler) shows, Snowy Owls certainly do catch ducks. I have just read that Snowy Owls also catch and eat fish, which I did not know. I read this information in a bird guide, written by Chester A. Reed in 1906... 111 years ago. He states: "...they will frequently kill animals or birds as heavy, or heavier, than themselves...They also catch a great many fish; these they get in shallow water among the rock-weed covered stones, by reaching down quickly and seizing their prey in their strong claws". After reading this, I switched over to Wikipedia's photos of Snowy Owls to see if I could find one in which this magnificent bird was catching a fish. I couldn't find a single one. However, I am prepared to accept that Chester Reed's claim is accurate. The only time I seen Snowy Owls, however, is when they occasionally migrate south in winter to a the nearby Holland Marsh, in southern Ontario, where I live, and they spend the cold winter months hunting mice, voles, pigeons or the occasional rabbit.
Please comment if you wish.