My husband is really into bird watching and he's tried to get me into it as well. This is only fair as my secret passion is fashion week, so I keep trying to get him interested in that.
He's a member of a couple of bird watching societies. Specifically, the National Audubon Society and the American Birding Association. These are two of the biggest bird watching communities around. There are local chapters for each, but the broader, National scale level is what keeps them all together.
The work that they do is pretty great. I'm not necessarily the biggest fan of birds (I appreciate them) as I would rather have a cat or a dog, but I'm enjoying learning about them.
Each bird watching society has events, trips, and charities that they work with. Donations are used to help keep the organizations afloat so that they can continue to preserve things.