Your edits are actually really decent. If you plan to do more of these edits I would say to take note of the light-source and make the whole sprite compliment the light-source. The outlines need to be fixed and not all jagged and blocky. Froslass said most of what was needed to say. Keep spriting! :D
I can see you're new. But that's ok, anyone starts as a beginner. There is always time to learn. =)
Going back to the bird, it's wing seems to make an unnatural bend near the base of the wing. It might have been like that when you took it off the original sprite but it wouldn't hurt to fix the parts a bit before putting them on a pokémon by adding a few pixels. As for being 'authentic' I can just see what parts you used and what not so it cannot be called your own art entirely.
Regarding what Logiedan said, he means that you may sprite in your own style as much as you like, as long as the art pieces you made are not made from any pokémon sprite but entirely from your own mind. The best way to scratch is by sketching a base of what you want, be it on paper and scanned in or directly in paint or whatever program you use for pixel art, and then trace it pixel by pixel and finish it by coloring and shading it.
If you want to keep your thread you'll gotta make a few of your own 'scratched' pokémon.