Hi, I'm Matt and can create your animation (7+ years of multimedia and animation work, mainly web/javascript).
Do you require "inner" complex animations of the elements e.g. like wings of the birds? Then this would be quite hard and disregard this bid. If not, then I'll create a javascript animation so it will run on a web page and will also screencast it to a video.
Looking forward to your reply with more details,
Matt