This is a very good photo according to me as -
1) It highlights the purpose of the challenge
2) The moments/subjects like this are difficult to capture and are not something which one witness day to day
3) The lighting and the focus is good.
Few suggestions which would have improved it further -
1) If the backround was more creamy blurr (again that depends on the lens .. so if you dont have the better telephoto lens then nothing you can do)
2) If the subject was on the right 1/3 frame rather than on the left unless you wanted to crop out something from the right frame
Nice capture! The birds are blending in to the yellow-green in the background; possibly a hue-shift from yellow-green to green and a slight desaturation of that would make the birds stand out more.