COMPOSITION... Since you went to bird park, I take it there was lots of fauna around to photograph, so the subject wasn't in short demand :) But the timing was good to get these two birds in the position they are! Glancing at the comments it seems its not only me that would want to see less of the top green portion of the photo, but instead of including the feet, i think its nicer if you make it a landscape crop and take out the protruding twig on the bottom... Nonetheless, I like the tree which runs down the right side of the photo and gives the viewer an idea of where the birds are looking. Effective use of DOF - makes the subject really stand out.
TECHNIQUE... I had no idea the Sony DSC-F717 had the capability of such narrow DOF (unless you were really close to the birds...)... at a decent distance, at F2.4, even my camera can't reproduce what you've done here... Exposure, image quality is great, though the image can stand to use some sharpening. (Sometimes I leave the sharpening alone if I'm going for a soft look so this sometimes falls under the realm of creative license).
The symmetry of the two birds is great. I'm a bit torn over the tree, though. Cropping it out would leave their heads too close to the edge of the frame, but it's also distracting. Too bad you couldn't get the shot from an angle which excluded the tree. Otherwise, fantastic. Getting a good exposure on those white feathers is no easy trick.
Very cute photo here of the birds. You wonder what they are actually up to. Nicely focused. Shows good detail and depth. I kind of wish I could have seen a little more of the birds and a little less of the green at the top. Their back ends and feet are cut off. My only complaint. Good luck in the challenge.