Grey Headed Wagtail.

 Grey Headed Wagtail twitch at Thornton! Only one previous record of two Grey Headed Wagtails at Rutland in 2001, so is this bird a Leicestershire first?

 Some shots of it stretching. Part of the upper chest band is just visible.

 The head is reminiscent of Lesser Whitethroat.

Yellow Wagtails are elegant, but the contrast of the yellow and grey make this a stunner!!