A walk around Buckenham Marshes is glorious on a windswept winter’s day. Yet for a truly remarkable experience, wait until twilight, that liminal time between dusk and nightfall which comes early in the dark half of the year. Sit by the river or settle down inside the cosy bird hide with a blanket and hot flask. The red sun sinks as flurries of wintering waterfowl finish their business of the day, while out on the marshes rabbits are just emerging from warrens to sniff the frosty air. Look closely! You might see a deer, stepping with nervous elegance in the shadows at the edge of the wood.

The last hour of light is corvid time. They’re predators with beaks like weapons, yet the evening ritual of these clever birds is a thing of beauty, wild and free. Their broken voices lift, a harsh chorus of croaks and caws, cryptic conversations known only to their kind. Single birds break from the wheeling cacophony sending out siren calls, returning with more in ever growing circles. Several thousand rooks and jackdaws rise to the tops of skeletal trees like torn fragments of the night. As they settle, the tumultuous noise subsides to silence. Nature is at peace.

Mark Cocker’s book Crow Country mentions an old East Anglian adage “When tha’s a rook, tha’s a crow; and when tha’s crows, tha’s rooks”. That’s how you know, a Crow in a crowd is a Rook. A Rook on its own is a Crow.