One cold night was all it took to immobilise the lake’s surface. A thin sheet of ice, but thick enough to take the featherweight of black-headed gulls, loafing around as though nothing were amiss. The only thing that ruffled them was the sudden arrival of a chunk of bread. Every gull on the lake converged on it almost at once, squabbling and skirmishing with raucous cries. When the fighting was over they wheeled back down to the ice and came in for a slippery landing, triggering an incredible series of noise each time a pair of feet touched down. The thin ice sheet whispered, creaked and rustled at their touch, the audible tension of the boundary between solid and liquid.
On the more sheltered side of the lake open water persisted. Here sat two great-crested grebes, floating in circles like ducks on a village pond. Their instinct is so much wilder, to move and dive out in the deepest water. They looked disgruntled to be hemmed in: grumpy grebes.
Two mornings later a thaw began to set in, though ice prevailed. The black-headed gull squad was now 100 strong and sheltered a handful of common gulls and a single lesser black-backed among their number. Close to the lake’s edge a mallard and moorhen appeared to be engaged in an ice skating race. Travelling on converging diagonal paths, they each headed towards a small island in a hurried half-walk, small steps interspersed with longer glides over the melting ice.