Birds fly. It’s the thing everyone knows about birds: they fly. Yes, yes, penguins and ostriches – okay there are exceptions. But by and large, we think of birds as flying.

There are some who really do. Crows, gulls and birds of prey, for instance, have taken to the air like fish to water. Show-offs. And geese, honking as they go. Why do they honk? Just to keep the group together or does it help them breath as they head in formation for the front line? It always sounds like desperate boasting to me. Made it, Ma. Top of the world!

But I digress. Your average garden bird isn’t a fish in water up in the air. It would much rather be perching on a twig, singing arias. It will run rather than fly, and if it has to take off, it treats it like crossing a river on slightly…