Great observations Fenders, in fact I've used predators as an indication that fish are around versus the other way around. On several trips on lakes or rivers I've used where birds of prey are targeting there search as an indication as to where fish are concentrating to my advantage. Once on the Clark Fork in Montana I fished several sections of river with no luck but from a distance watched two Osprey circle over one section of river. When I hiked down there the Osprey cleared out and sure enough I started hitting some fish in that section. I moved on and the Osprey moved back. I continued to not catch fish so I moved back to the section again and guess what, I caught more fish. In fact in that section I landed the largest Brown trout of my life all because predators were present. Ira..