After escaping to the Lake District to visit his friends the Wordsworths, Samuel T. Coleridge was on the overnight coach to London, preparing to face family responsibilities and the reality of earning a living.  At dawn, he was mesmerised by a sight over the wintry fields:

Starlings on a vast flight drove along like smoke, mist, or any thing misty without volition – now a circular area inclined in an Arc – now a Globe – now from complete Orb into an Elipse & Oblong – now a balloon with the car suspended, now a concaved Semicircle – & still it expands & condenses, some moments glimmering & shivering, dim & shadowy, now thickening, deepening and blackening!

In his fascinating biography Coleridge: Early Visions Richard Holmes notes how this vision would haunt the poet long after.  It was

some sort of self image for Coleridge, both stimulating in its sense of freedom, of “vast flight”; and menacing in its sense of threatening chaos or implosion, “Thickening, deepening, blackening”.

This excellent video shot at Otmoor, near Oxford, captures the display before the starlings settle in their roost, building up to an astonishing climax, when the flock becomes almost impossibly dense.

The photograph is taken from a Guardian gallery of starling photographs.