Birdbath to Water Feature

I would appreciate some advice here. My garden club donated a birdbath to our local nature preserve. {See the picture} I would like to add a reservoir and pump to this, as unobtusively as possible to keep the water fresh in it without preserve personnel having to come out and fill it on a daily basis. I would like to make it solar powered. I envision a really slow moving drip sort of water feature so as not to scare off the birds. Do any of you think this is feasible? I could get funds from both the garden club and the preserve for the equipment part of this, but I would like the mechanics to be as simple as possible. I would appreciate all advice since I have never had anything but a table top fountain. Thanks in advance,
Martha

Hi
I had a birdbath that I also wanted to make into a fountain. I purchased the little solar fountain off of ebay. At first it ran really well, but the filter is small and it clogged almost every day. Then it just quit working. I did purchase a 2nd one and it did the same thing. I think that the bird waste was just too much for the small filter to handle. This is the one that I purchased, I'd stay away from this one. Someone may have had success with a different one, hope we hear from them.