This week we're tuning in to the science of birdsong, including parents who talk to their eggs to warn them of high temperatures, and how traffic noise means young birds are taking longer to learn their songs. Plus, in the news, scientists grow beating hearts in a laboratory culture dish; why the plastic you recycle isn't going where you think it is; and why a long working week might be the death of you. Like this podcast? Please help us by supporting the Naked Scientists