First, thanks for taking on the task of starting this community! I'm enjoying it so far and have posted a few birds myself.
I've been a mod of a few subreddits, both small and large. I don't think you need a whole lot at this stage but it might be worth putting in place some rudimentary rules so that, if you need to remove posts or comments, you can point to a rule when you do so. These can be pretty simple and obvious like:
- Be nice! Don't be rude to others or your comments will be removed and you may be banned.
- All posts must be related to birds.
- If you are posting someone else's content, provide attribution.
Another thing that could be useful is a bot that cna label posts with the bird's species when they are identified. I'm not sure if there are good bots that could just be dropped in place, but it might be worth looking at what is used in /r/birding.