the seagull shot is sharp where it counts.
Seagulls are great practice for flight shots.
looks a little hot to me.
I quite often use centre weighted metering for bird photography and compensate as necessary. Birds are quite often a smaller component in the frame than say a landscape.
As far as the d2x and how its auto focus works (together with suggested
modes for different situations, this article:
http://www.nikonians.org/html/resources/nikon_articles/body/multi-cam2000_af/multi-cam_2000_9.html
this link above covers the part which mentions the lock on feature.
By all means go back to the intro and read the whole article from the beginning as it is quite detailed and well worth a read
not sure if this article has been mentioned before.
Steve