The 22 year old Macmillian Field Guide to Bird Identification (Harris, Tucker & Vinicombe) is still, in my opinion, a gem of a book and it has proved it again on the subject of the ageing of this species. The blackish sub-terminal bar behind the pale tips to the greater coverts (which can be seen clearly on at least 2 of my pics), also on the tertial & tail feathers, ages it as a first-winter.
Also interesting to re-read the discovery (found by Jack Donovan) of Pembrokeshire's first & only previous Isabelline Shrike at Nine Wells in Birding in Pembrokeshire (Green & Roberts) p.40 - it was on 27th October (so close!) 1995 and according to my account it went to roost at 4.50pm.
