Our flat here in N.E. Switzerland is metres away from a belt of woodland. In winter, the view to the north is tall tree trunks with Lake Constance and Germany beyond, and in summer we have peaceful shades of leafiness on the other side of the balcony railing. One effect of this is we get a motley selection of birds whizzing past at all hours of the day. Another is the fact that the dawn chorus is all the alarm clock you need in summer, which is sometimes a good thing…

I’m not very good at birdsong. In fact until a week or so ago, the only ones I could identify by the noise they make were crows and cuckoos, which are kind of obvious, and woodpeckers, not quite the same thing. But at some point this spring I became aware of a different bird voice, one with a very…