While it may simply have been a result of the low lighting, your picture has light qualities of Rembrandt's paintings. The composition is good, as well. I would try dodging the head and neck of the tallest bird and toning down a bit the lighter parts of the other two birds, but in a subtle manner. That would lead the eye to the taller bird making it the center of attention by size and brightness.
The new radial filter, reversed and with a fairly large degree of feathering, would be an ideal tool to accomplish that. Congratulations, though: the picture is quite good.