Sunday, 25 January 2004

25th January 2004 Newhaven Ouse Project 11.00am – 12.45pm. Calm, sunny and even slightly warm! Gills Lap, Ashdown 2.30pm – 3.30pm, Burgess Hill 4.00pm

Shelduck 2
Lapwing c.300 in nearby fields
Snipe 1 Ashdown
Black-headed Gull c.300
Common Gull c.250 mainly ad.w but a few 1st-w
Herring Gull c.25 mainly adults with most close to fully acquiring s/p
Scandinavian Herring Gull 1 adult winter 12.30pm – 12.45pm
Whilst scrutinizing the regular large flock of Gulls consisting of mainly Black-headed and Common Gulls but intermingled with lesser numbers of Herring, Lesser and Greater Black-backed Gulls we noticed a very large, dark-mantled Herring-type Gull with a strikingly pale iris. We immediately suspected it was an argentatus Scandinavian Herring Gull and set about comparing it with the other Herring Gulls alongside. It was considerably larger and bulkier than any of the argenteus Herring Gulls (appearing only slightly smaller than some of the Great Black-backed Gulls present) with its size, rendering it taller, making it easy to follow as it walked amongst the flock including behind argenteus Herring Gulls. It was clearly larger, heavier and longer-billed than the argenteus Herring Gulls, its bill being yellow with a dull red spot on the lower mandible at the gonys. Legs pink. Large-headed being heavily streaked brown being particularly dark around the (strikingly pale) eye. The brown streaking became heavy brown blotching on the lower nape and on the sides of the breast. The large dark-streaked head combined with a thickset neck gave a Glaucous Gull-like impression, but if anything, the contrast of the dark head with the very pale iris, gave it an even fiercer and more evil look! In contrast, the majority of the adult argenteus Herring Gulls present had already acquired their summer-plumaged white heads and although some retained some fine streaking. Overall, in comparison, the largely white-headed argenteus looked considerably rounder-headed and smaller-eyed giving a far cuter appearance. Upperparts including the mantle, scapulars and coverts were a uniform dark-grey with a deep bluish suffusion close to the colouration of the surrounding adult Common Gulls. The upperparts were therefore noticeably darker than the argenteus Herring Gulls having the typical pale-grey upperparts in comparison. The dark upperparts contrasted with a broad white tertial crescent. An obvious tertial step was prominent. Underparts and tail wholly white. Primaries extended beyond the tip of the tail with P10 appearing largely white and large white tips to other longest primaries. After c.15 minutes all the Gulls took flight, when at first we followed the bird through our telescopes as it flew towards us, but was then easy to locate in flight through binoculars appearing heavier than the accompanying argenteus Herring Gulls being noticeably barrel-chested and having a slightly stiffer-winged in flight, reminiscent of a Glaucous Gull. In flight we concentrated on the wing-tip pattern that revealed a reduced amount of black in comparison with the argenteus Herring Gulls. Whereas most of the Gulls circled and landed the argentatus flew-off strongly south until lost from view as it continued over the Tide Mills.   

Further research suggests that this bird is likely to originate from the northern limits of the range of argentatus as those represent the largest and darkest-mantled individuals of the clinal variation exhibited by this subspecies. Furthermore, due to its large size, we suspect it was a male.

Lesser Black-backed Gull c.5
Great Black-backed Gull c.15
Skylark c.6 roadside
Stonechat 2 Ashdown
Coal Tit 1 Burgess Hill