About the ISO, generally speaking....high ISO isn't necessary....."IF" you have plenty of light. What is necessary is a fast shutter speed to freeze motion and eliminate lens shake from the telelphoto lenses used for these kinds of shots.
Again, great capture. The detail is there! Look at the eye,......WOW!
Well done! Went to Alton, IL to photograph Eagles last week. Ran into snow storm making it difficult to get good phtos. When I check all of my photos out, I hope at least a couple will turn out like yours. Excellent! Thanks for sharing.
No don't worry about it. I was just wondering about how close you were to the bird to get it with a 230mm. Very impressive you were able to get so close.