As Allen mentioned, very nice background, good example of their eating the head first.
The bird was lit from high to the left, which makes it a challenge to get even illumination.
Agree with your self critique about the angle. Your angle up to the bird however was very good. So many of the osprey shots, mine included, are at a pretty steep up angle.
I like the colors in the perch, but it is a bit overpowering size wise. If the bird was turned our way, a modest crop from the right to downplay the perch would have worked.
Hope you get some more opportunities with this nice background