The first shot looks to me like it could be improved with only a little post processing, while the second looks to me like the camera focused on the apple instead of the bird. Here's a great article about getting the best sharpness out of a 510:

http://www.wrotniak.net/photo/43/e510-fs.html

If your experience resembles mine (with my first DSLR-an E-1) your shots will continuously improve with practice. Good shooting.

Rocky
http://bl3.smugmug.com/gallery/2559031_YMWkb#134634697_uYbjn