Country diary: worms lose their grip in a deadly tug-of-war

Bishop Auckland, County Durham: The earthworms have little defence against marauding birds in this uneven struggle amid the mud

Mud: boot-sucking liquid earth, the winter hazard that country walk footpath guides never mention. And it looks like horses have welcomed every rambler who crossed this stile, surrounding it with a morass of water-filled hoof-holes.

Too far from home now to turn back, so I press on, sticking close to the hedge. And while I unburden my muddy boots on grass tussocks, a song thrush hops across the waterlogged field, just a few yards ahead. It pauses, cocks its head to one side, as if listening, then strikes and yanks an earthworm out of its burrow. It catches four more in quick succession, all driven to the surface by days of heavy rain.