from Alan Dean
Hello Martin and thanks for the response.
Below is a composite image showing
(a) a photo of the St Agnes, Scilly, Chiffchaff from October 2011 (the bird I have long featured in discussions as a classic example of a ‘grey and white’ Chiffchaff and with which you will be correspondingly familiar);
(b) a copy of the image by Anthony McGeehan of his suggested abietinus on Inishbofin in October 2014 (I trust Anthony is happy for me to repeat it here).
I do not suggest that either image is colour perfect nor that their appearance in the field would not vary somewhat from their depictions here. I do suggest that there is a close similarity between the two individuals in these photos and that they are ‘the same kind of beast’. I have selected an image of the St Agnes bird which has a somewhat comparable posture to the Inishbofin bird.
There are further images (and plenty of discussion!) of the St Agnes bird on my website: http://deanar.org.uk/tristis/tristis.htm