We stand on a raised bank on Hickling Broad, clapping hands and stamping feet against the December chill. A blackbird sounds its excitable pre-bedtime “chink, chink” alarm. After a day of mist and drizzle, the winter light is fast draining into dusk. Time to be heading home, you might think. But the day’s defining performance is still to come. First, a dark shape appears, drifting low over the marsh. Our binoculars reveal the signature shallow-V flight profile of a marsh harrier, returning to its communal roost. No sooner have we picked out three more, straining the limits of our vision, than a clarion bugling diverts our gaze to a line of larger birds emerging from the south. Deep wingbeats and outstretched necks identify these as cranes, Hickling’s speciality. Their high, rolling calls bring a brief blast of northern taiga before they, too, drop down into the reeds. Even now, the show isn’t over. With the landscape reduced to silhouette, a murmur rises in the north, quickly swelling in volume, like a distant advancing mob. “Pink-feet,” says Mike. “Look up.” And here they come: a straggling army of pink-footed geese materialising in waves against the last of the light. The thin etch-a-sketch skeins thicken, converging overhead in a milling canopy of birds thousands-strong, their individual voices lost in one overwhelming clamour. We stare up in awe as they pass, then they’re gone. With the sky silent, but our ears still ringing, we turn back towards the car park.