They look sharp to me. Birds are tough because they are always in some grass or brush and it tends to distract at times. Sometimes it works for you, and sometimes it hinders. Even an F2.8 lens has a hard time on pictures like these. I like the first picture as the background is less distracting. Magazines usually like that so they can put their writing and such on top and not have it mingled with brush/grass.
Oh, I also like eating chuker...
shawn
