I am an avid birder, but bird bath maintenance is difficult only in that the birds constantly poop in it and I should be scrubbing it out constantly.

I used to have a pond and I remember once the bacteria/natural cleaning mechanisms are in place, they are fairly low maintenance. But, if I set up my pond as a bird oasis with shallow areas for them to bathe, will the poop overwhelm the filtering capacity? I'd rather not have an electric pump and filter. Am I asking too much?

Any suggestions?

Thanks!