On the morning of Sunday 10th April, Peter and James Kennerley and Steve Abbott trapped a bright and quite short-winged Phylloscopus, which went into the bag as a 'Willow Warbler'. During processing, the wing was quite short at 57mm, yet had an emargination on p6 and the plumage was especially bright - alarm bells range, and there was the thought it might be Iberian Chiffchaff.
A full suite of measurements was taken, which when applied to the Svensson MCV was calculated as 74.9, when >73.2 equates to Iberian (see http://www.surfbirds.com/Features/ib...ibechiffs.html for some explanation of the MCV and Ibe Chiff ID).
Unfortunately, when released the bird was not seen again and it was not heard to call or sing - a short tail measurement probably means it was a female.
James Kennerley has a set of photos of the bird here - http://www.pbase.com/jameskennerley/iberian_chiffchaff compare these with the Common Chiffchaff trapped on the same day - http://www.pbase.com/jameskennerley/chiffchaff