Imagine a handful of fragments flung from a giant’s hand: a smudge, a stain, a dark shadow against the sky. The shape stretches, shifts into a thumbprint then swirls and dances into the smoke emerging from a genie’s lamp before it tips amd spills into a wide arc, now shards of glass, diamond splinters glistening in the early sun. At the susurration of thousands of small wings passing overhead the breath is punched out of me and I’m crying – sobbing, in fact, sideswiped by wonder.

It’s early on the first Sunday in September and after getting up in the dark we’re at Snettisham on the North Norfolk coast, joining a small crowd for the phenomenon that has become known as the Knot Spectacular. Knot (perhaps from their call which my bird guide gives as knut although its Latin name Calidris Canutus recalls the 10th century king who famously tried to hold back the tide) are waders, long-distance migrants that arrive in the UK in huge flocks in autumn from their breeding grounds in the high Arctic to feed on mudflats and estuaries. The spectacle occurs most dramatically at times of exceptionally big tides – this weekend’s was somewhere over eight metres – when the birds are pushed off the mudflats by the incoming water and take to the air in their thousands. In winter plumage the birds are silvery-grey on top but white underneath which creates the jewelled glint and gleam when the sun catches them.

Our route takes us along the sea wall, between the ramshackle assortment of shacks, caravans, chalets and huts to our left – I spot a hand-written notice ‘CHARITY YARD SALE 11 am. SUNDAY’ – and the sea on our right. There’s a thin covering of cloud and a biting wind. I feel the weight of expectation, anticipation, We stop often to look through the scope at the foreshore, dark with what Andy calls The March of the Oystercatchers. There are pockets of ring plover, hard to make out against the pebbles, and bar-tailed godwit; a skittering of wagtails and, as the strip of mud is shrinking fast, increasing numbers of knot, jam-packed and scurrying as if trying to outpace the tide. A few early flurries and here comes the sun and already one scattering of slivers follows another, spinning, wheeling and swerving, white breast and underwing flashing and shimmering in the early sun.

It’s over before I’m ready. Suddenly the watchers are hefting their tech and heading for the hides and I’m left unsteady, almost alone, surrounded by sea heath and the startling blue of viper’s bugloss, trying to make sense of the migrant crisis I have just witnessed. Unlike its human equivalent, there is something both extraordinary and beautiful in the mass displacement – at least to us.

(C) Danielle Jones (Teale) Dance, Collective IDentity, written by Kate Swindlehurst