Bob Flood and Martin Garner
.We have received several interesting responses to the posting on Atlantic Fulmars with dark subterminal tail-bands (technically subterminal because Atlantic Fulmars have narrow whitish tips to tail feathers).
Brett Richards has recorded similar birds from Flamborough as follows: On 4 January 2009, seven Blue Fulmars were seen. One had a very dark, almost blackish fairly narrow subterminal tail-band, and this was the darkest part of the plumage. On 5 March 2012, eight Blue Fulmars were seen. One had dark/dusky tail corners. So, it seems these Arctic breeders with dark subterminal tail-bands make it to the UK. Beware headland watchers!
Darryl Spittle found a photo of an Atlantic Fulmar with a partial subterminal tail-band in his fulmar photos taken in Spitsbergen in June 2012.
We also heard from Hadoram Shirihai. In summers 2004–8 he made a census of plumage-types across much of the main breeding areas, concentrating on Iceland, Jan Mayen, Bear Island, Svalbard, and the Arctic northeast Canada. In this survey he also noticed that intermediate and dark morphs can have adark subterminal tail-band. He noted, as we did in our photographs and video, that the subterminal tail-band is variable; narrow, wide, or only on some feathers and may be asymmetrical. Although Hadoram does not have his notes with him, he seems to recall at least c 5 % of the birds in some locations exhibited this feature, but it was most frequently observed in Svalbard, with some as far south as Jan Mayen and Bear Is. He agrees that these birds are not Pacific Fulmars.
Possibilities currently under investigation by Bob and Hein van Grouw include: ancestral gene from Pacific Fulmar, gene recently passed on by Pacific Fulmar, aberration in the way pigment granules are distributed (inheritable or not inheritable). So, even the thought-to-be familiar Atlantic Fulmar is in fact full of mysteries and puzzles (of which there are more to come)!
Video of dark-tailed bird which sparked the latest explorations: