Welcome to DPChallenge. This being your first challenge I feel it only fair to point out a few thing to help you in future challenges.
First off don't try to crop in on something small in a photo. You will end up with an image that looks very boxy, meaning you will have a very pixelated photo and see each little color box to your image when you try to make it larger. Which to me is probably what you did here.
Next try to get as close to 640 x 480 on your finished image everyone around here likes the larger sizes shows more detail.
Finally make sure your subject is in good focus. If the bird is your subject it should be in better focus.
Hope this helps you some in future challenges. And yeap I made the size mistake too in my first challenge. A lot of people do.
sorry to say way too cropped and too small read this before your next submission please..it will help: //www.dpchallenge.com/tutorial.php?TUTORIAL_ID=26