After following instructions given through tree icon, my video hasn't appeared in forum thread. It is suggesting it didn't upload. As I have a youtube account I thought it would be easy from there and that was an option given too.
I would like to encourage others to share video footage in this thread too so it would be helpful to know how to achieve this.
The thread I was trying to upload to is this one http://www.gardenersworld.com/forum/wildlife-gardening/garden-pond-wildlife-photos-video-and-ids/451633.html