On my personal memory map of favourite local walks, this tree-lined former railway line is labelled Boulevard of the Bullfinches: they are always here in winter. Storm Arwen blew autumn away in a day. Sub-zero overnight temperatures have left the old track bed iron-hard. Frozen grass and fallen leaves, fringed with ice crystals, crunch underfoot. There is a brutal, eye-watering north wind, so I walk head down, face numb, shoulders hunched, gloved hands thrust into pockets. Glancing up, I’m brought to a halt by a briar rose sprawled across the path, blocking my way, blown down from a birch it had scrambled through. Its long, arching stems flail in the wind, like a wounded animal, flaunting claws of lacerating prickles. The very thought of walking into them hurts. Then, flying towards me, a cock bullfinch settles among the rose thorns. Black mask, dove-grey wings, cerise chest feathers: smooth, perfect plumage without a feather out of place. A gift on a bitterly cold winter morning. Shivering under four layers of clothing, elated with my good fortune, I wonder where this vulnerable bird found shelter through that long night of window-rattling, freezing winds while we lay awake, listening to fences splintering and bins blowing away. Bullfinches seem to like this two-mile stretch of linear woodland, probably because it offers a plentiful mix of food sources and the security of thorny cover. Today’s bird is feeding on stinging nettle seeds, but the winter menu includes dock and rosehip seeds, ash keys and the pips in mummified brambles that no one picked last autumn. As spring approaches they’ll switch to swelling flower buds of blackthorn and wild cherry. When the wind lulls, soft contact calls from the rest of the bullfinch family – the hen bird and two juveniles – drift down from hawthorns overhead. They’ll stay together as a family group all through winter. The parental pair bond may last a lifetime. Frozen fingers fumble with camera settings: there’s time to take a few photographs before they all take flight together, bounding away down the track towards three more months with winter days like this.