Appearance of 'B/ue Fu/mar' and potentia/ con fusion with 'soft-p/umaged petre/s' their underwings are subject to a changing amount of shadow, but Blue Fulmar really does have variably dark, smoky-grey underwings. Even lightly-coloured Blue Fulmars show dark underwings. In fact, irrespective of how dark the bird is, the underwings appear to be its darkest part. While Fulmar has limited dark on the underside of the outer primaries and adjacent primary coverts, with a narrow darker 'strip' along the underside of the secondaries, the remainder of the underwing is pure white. Blue Fulmar has grey underwings with grey axillaries and underwing-coverts. In particular, the under primary coverts can stand out as noticeably dark, almost blackish, as can the outer primaries . In turn, this makes the inner primaries stand out as an often conspicuous pale wing flash . Depending on distance, other differences from typical Fulmar can be seen, which include head pattern and bill markings. Blue Fulmar often shows an obvious blackish 'shadow' around the eye. Typical Fulmar also possesses this mascara-like mark at the front of the eye, but Blue Fulmar not only shows a more extensive patch at the front, but also may have a dark area around and behind the eye. On several individuals that I have seen, the bill of Blue Fulmar has shown a continuous dark band which runs as a diagonal from the upper mandible to the gonydeal angle on the lower mandible. This can vaguely recall the bill pattern on an adult Ring-billed Culi Larus de/awarensis. Bill colour also tends to be yellower on Blue Fulmar. I accept that there may be no merit in pointing out these bill pattern details, since this could simply be individual variation (the view of Bernard Zonfrillo) . Taking all of the above together, is it possible to confuse a Blue Fulmar with a 'soft-plumaged petrel' Pterodroma feae/madeira/mol/is? I believe it is, especially as the peak time for sightings of soft-plumaged petreis, the month of August, also witnesses the largest movements of Fulmars around the Irish coast which, drawn from a wide catch ment of the northern Atlantic, usually contain a few Blue Fulmars. For an observer unfamiliar with Blue Fulmar, it may come as something
of a surprise to encounter a lone seabird flying in strong winds with an easy, languid style and flashing dark underwings (a 'diagnostic' feature of soft-plumaged petreis). The classic Fulmar shape can be disguised because the bird is grey and uniform and, depending on the strength of the wind and state of the sea, the bird may be gliding and arcing high , and holding its wings in a manner which makes them look quite pointed and un-Fulmar-like (as with the Blue Fulmar depicted in Dutch Birding 15 : 91, plate 52, 1993). Rare seabirds also have the unfortunate habit of flying alone, making on-the-spot comparisons with commoner species impossible. A lone Blue Fulmar has caused consternation on at least one Irish seawatch (pers obs) . Unfortunately, field experience of soft-plumaged petreis from land-based seawatching is very difficult to acquire. I have been extremely lucky to see th ree individuals, which can only stand as a basic introduction to the subject. Nevertheless, compared with even the most troublesome Blue Fulmar, there are differences. The flight style is distinctive and 50 too the constantly angled, boomerang-shaped wings . More explicit field points are a pure white belly and underparts and almost evenly dark, blackish underwings. Softplumaged petrel also has white 'armpit' triangles (which may be difficult to see) and lacks the normally striking pale flash on the inner primaries shown by Blue Fulmar. On the latter, this is visible both from below and above . The upperwings of soft-plumaged petrel not only lack any equivalent wing flash, but they are significantly darker than in any Blue Fulmar I have seen. I am grateful to Bernard Zonfrillo for supplying me with references and for helpful discussions. References Fisher, J 1952. The Fulmar. London. van Franeker, J A 1995 . Kleurfasen van de Noordse Stormvogel Fu/marus glacialis in de Noordatlantische Oceaan. Sula 9: 93-105. van Franeker, J A & Wattel, J 1982. Geographical variation of the Fulmar Fulmarus glacialis in the North Atlantic. Ardea 70: 31-44.
Anthony McCeehan, 75 Lyndhurst Avenue, Bangor Bn 9 IA Y, Northern Ire/and
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