An anonymous reader writes:
Songbirds living along the Hudson River in New York state are exposed to levels of PCBs that don't kill them but do disrupt the songs they sing, reports a team of researchers from Cornell University. Their study reveals that birds residing in regions with higher environmental PCB contamination levels have higher total blood PCBs, which affects their singing behaviour: the team found these species' songs varied predictably based on their PCB load, and also based upon the type of PCBs. Thus, the scientists suggest that another of the many toxic effects of sublethal environmental PCB pollution are neurological effects that translate into observable behaviour changes that disrupt song quality used by birds to communicate.
