Bird News from Nial Moores and Park Meena
Gyeongju and Guryongpo Peninsula, February 3rd
Day One of a five-day survey of sites that have held Scaly-sided Merganser Mergus squamatus found a lot of ongoing construction, and no scalies. Happily, a quick 3 hours birding in subzero temperatures on the Guryongpo Peninsula was much more interesting. The first stop, in Seokpyeong Village, found two Light-vented Bulbul sunning themselves in some berry-laden trees. Along the coastline, in among a large number of Slaty-backed Gull (three main groups contained at least 1500 birds) were two Glaucous-winged Gull and a couple of fascinating ID challenges!
The first was a white-winged gull…It was clearly smaller than most (or even all) of the vegae, and images taken (taken through an ageing Nikon coolpix and a brand-new set of Swarovski gear – on which much more in a later post!) show its fairly rounded head shape and bill pattern more suggestive of Iceland than Glaucous Gull. Its primaries showed no dark markings.
Iceland or Glaucous Gull? Photos Nial Moores/Birds Korea
Such “glaucoides-types” appear to be annual in the ROK. Is this one an Iceland? A small (female) barrovianus Glaucous with an atypical bill pattern? Or is it one of the enigmatic birds described in Malling Olsen’s Gulls (according to which “An undescribed taxon might occur in N Russia:…smaller, tamer adults…brighter eye-ring and yellower iris; accompanied by smaller, grey immatures…a pair found nesting…female had bright lemon iris, orange orbital ring and measurements similar to large Iceland Gull…Such birds were even found at four sites in Novaja Zemlja” P.216, First edition). How too about the bird identified as an Iceland Gull in the Birds Korea gallery (at: http://www.birdskorea.org/Gallery/Species/BK-GA-Larus-glaucoides.shtml)?
The second ID challenge appeared at first sight to be a fairly straightforward adult American Herring Gull (recorded scarcely annually in the ROK).It was heavyset and glaucous-pale on the saddle (like most such adults here – presumably as from the paler, western part of the population); dirty-brown collared, with primaries showing much black and thick white tips; had very pale eyes (with orangey eye-ring), and a pale-based bill with a fairly obvious dark mark. However, the undersides of the primaries were pale grey, and there was some grey admixed in the primary black suggesting a hybrid origin.
Iceland or Glaucous Gull? Photos Nial Moores/Birds Korea
Hybrid American Herring and Glaucous Gull have been recorded in North America and Europe. Is this the explanation for this striking individual? As with the white-winged gull above – all comments welcome!
Other birds of note in the short time available found on rough seas included two Black Brant, 38 Rhinoceros Auklet but only 17 Ancient Murrelet, 50 Harlequin Duck, at least 500 Pacific Loon and my personal highest day count to date of Red-breasted Merganser – with at least 1600 present.
Pacific Loon. Photo Nial Moores/Birds Korea
In NW Europe there have been large numbers of Iceland Gulls in relation to typical winters and a high proportion of these are of the Kumlien’s form which may, or may not be, an intergrade between Iceland and Thayer’s. There appears to have been quite a displacement of these birds following a severe winter storm which originated in the Davis Strait between E.Canada and Greenland. The Sibley Guide treats it with Thayer’s Gull: the Audubon guide with Iceland. I see there’s been a lot of claimed Thayer’s and at least one Kumlien’s type on the US Pacific coast this winter (http://seagullsteve.blogspot.com/2012/02/iceland-gull-cometh.html).
If I saw this bird in the UK at present I would suspect a near Iceland intergrade, Kumlien’s. Although I haven’t seen ‘barrovianus’ Glaucous Gull all I have read suggests that it is smaller form of the big, small-eyed and mean-looking hyperboreus/pallidissimus races with the typical black-tipped pink bill and a less strong tertial step and a ‘herring’ gull head shape.
This bird’s head and bill shape and proportions, recalling Common Gull (L. canus), are so typical of all the Iceland Gulls which I have seen and it has the typical long primary projection and very little tertial step of that species.
However, this isn’t to say that it could still be from the mystery ‘Siberian’ white-wing!