I must say..
I really liked the animation,i'm not going to talk about the joke now because i understand you wanted to practice and not make something to get place in the frontpage.the animation was very smooth and the charcter movement was great.i think the bird movement is ok to but you can work on it if you like.sound was good too but it could be really nice if you add some forest\jungle sounds.and one more thing,please add a newgrounds preloader to your next flash it is really really easy.
and about the joke(sorry i have to haha :D) it could be funny if after writing "don't kill...." you would write just kidding! don't look into a gun!................its fu**ing stupid!.................seriously don't do that.
good luck :D (i know this is long im sorry..)