I think the first one should introduce the forum, channel, and collaborative concept. The members of the videos can change from video to video depending on who wants to participate or new members joining in (remember this might create more interest in the forum). So if anything, members should have a subtitle, closing credit, or mini intro in each video they participate in rather than a specific introduction in the first run.
This was the original concept I came up with for a first video. So that's a starting point to think about.
The whole intro could be solved if you appear in the video with all your birds and a subtitle that says Alyssa. With so many participants, viewers may not remember people from video to video so having a long term intro/credits solution is important. This way you are free to actually present something that will interest the viewer rather than 10 people introducing themselves and not really getting to any point that would be of interest to unrelated (non-forum) viewers.