I suggest the title should say "Polychlorinated Biphenyls cause birds to sing a different tune".

In the context of Hacker News, the title suggested to me that someone had engineered a Printed Circuit Board that would interfere with birds' brains, perhaps by emitting magnetic fields to mess with their sense of north, or something.

Same, I had to scroll down until I found out it was a polycarbonated biphenyl then had a sigh of relief.

This is only tangentially related to the article but where I live there is a lot a wildlife, including many different species of birds. Some of these birds now sing songs that mimic common mobile phone ringtones. This is obviously not as bad as pollutants effecting birds behaviour but I think it's a great example of technology having strange, unintended consequences.

I wonder how these birds like tetrabromobisphenol-A (TBBPA) and deca-brominated diphenyl ether(DecaBDE).

I'm curious to see whether exposing the bird to helium has any effect.