I am not too sure , when I saw the fish in its talon , it did not move.

As for the "Bird saw the fish" - I too thought about this , because the Eagle was soaring for sometime before it landed.

My thought was wont the fish swim away?

Then the reason I thought it could have caught the fish was - the fish might have come to shallow water and the eagle caught it.

Hope this reasoning is possible. I am not sure

vikas madhav