Flight practice

I consider it a privilege to be able to watch the life of wild birds close up. I have my 28" computer on my kitchen desk, and I have been watching the daily life of an osprey family since the first three eggs in April until now when the fledglings are exercising their huge wings. 
In a few months they are probably leaving and flying who knows how far, thousands of kilometers.
What were they fed with when growing up? Fish. Raw sweet water fish.