Generally they are slightly over exposed, but not much.
The composition is good.
Unless the lighting is tricky I tend to rely on spot metering the bird, as that is what I want exposed correctly.
Light is key, I tend to aim for 1/500 sec and f7.1 as an ideal starting point, however I have no qualms about using ISO 3200, and running the image through noiseware.
What is your set up, are you using a tripod?