Great ID Challenge!
Not sure that the British list has an acceptable 1st autumn Collared Flycatcher, Enter: todays bird at Spurn. Readers will hopefully understand the enormity and potential complexity of such a claim. With wing length only in range of Collared and too long for any Pied; a Collared type tail pattern and primary pattern it mostly seems to fit the bill. There are one or two characters which we are unsure of, so a little work and investigation needed. A certain learning experience for all!
For now a photo of the bird in the field. Full details to follow here. On behalf of Spurn Bird Observatory we would be very keen to hear from anyone who has first hand ringing experience of 1st autumn Collared Flycatchers and of in-hand photos of same.