Many thanks for a fine photo from Helgoland.
Recently, Henrik Haaning Nielsen's NETFUGL photo 29. March 2013 of Cretzschmar's B. in Egypt was discussed.
An argument for Cretzs. B. was a reference to Svensson's and Beaman's field guides indicating C.'s rusty brownish vent/undertail vs. whitish on Grey-necked B.
Did You or colleagues consider this feature?
Mit besten Grüssen ,,,,,,,,,,,,,, C.
I think you mean these pictures http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=54684 which show obviously a Grey-necked Bunting for me. As in this bird the most remarkable features of the Helgoland-bird were the long and fine bill and the lack of a dark breast band, therefore the ID in both cases is finally straightforward in my eyes. Therefore no doubts about Grey-necked Bunting :-)
Many thanks for Your prompt and interesting specific comments.
So, I may add a note to Svensson's text and illustrations of Grey-necked's underparts.
Best regards & smile ,,,,,,,,, C.