Thanks everyone. The top goose, one farthest from me, is the one I added. I had the most trouble getting the reflection to look right so what I ended up with was a bit of reflection from the original oof goose and a bit copied from the other frame.
Good point about the water around the added bird not being as sharp as expected.
I would just like to add, I doubt very much I would have spotted anything if I wasn't actively looking for it, I think the merge works really well overall and the PS is great.
Jim, I think you did a good job too! I really had to search , altho once I discovered something, now I see it with no trouble at all! You did some cloning or some kind of adding to the water in the left 3rd of the image. There are some clone marks and repetitive patterns. Would probably not be noticed unless someone was really studying the image.