The first starling murmuration I saw was at university in Aberystwyth. Every year, as winter began to draw in, the starlings would congregate in a huge flock that undulated above the bay. The memory sends shivers along my arms even now, twenty years later: the flicker of dark shapes against a fading sky, the flurry of wings, before the starlings seemed to be sucked beneath the pier where they would roost for the night.