One of our prettiest birds - the goldfinch, Carduelis carduelis britannica. The latin name stems from its predilection for thistle seed, carduus being the Latin for thistle. They also, as one was doing this morning, eat the seeds from teasel (see January 3rd).
Frequently kept in the past as a cage bird because of its stunning appearance and pleasant song. It is also associated with Christ's passion in Christian symbolism because of the thistle/crown of thorns connection and the red around its face.
Donna Tart's Pulitzer prize-winning book was called The Goldfinch because of the role Carel Fabritius's 1654 painting of the same title plays in the plot. Hieronymus Bosch also includes one in his fabulous tryptich The Garden of Earthly Delights.
They often hang around in flocks in the autumn and winter, visiting thistles in field edges and rough ground. They have fairly distinctive calls in flight:
The collective name for them is a charm, which seems quite appropriate given their appearance. However I learnt from Mark Cocker's excellent Birds Britannica that the original word was the Old English c'irm meaning the tinkling sounds made by flocks in flight.