thank you for sharing the response from the university. I have never heard of the vinegar before! I think i'll put the copper tube back into the bird baths. I have to wonder if it was some kind of genetic thing even. Lots of other birds were drinking there, goldfinches, house finches, robins, and many more. I didn't find any of them dying....
I want to thank everyone who spoke up on this thread and offered their thoughts and advice. I am so glad to have found this site!
Thanks everyone!
