Friday, 19 April 2013

Iceland Gull (Larus glaucoides), 2cy, 16.4.2013, Kjul Strand, Hirtshals

This 2cy Iceland Gull was photographed on the beach east of Hirtshals Harbour in Denmark on April 16, 2013. It was colour-ringed on Gismerøya, Mandal (Vest-Agder) in southern Norway on Februar 2, 2013.

Friday, 5 April 2013

Dark-tailed 3cy European Herring Gull with a slight 'Nearctic feel'

The search for smithonianus in Denmark continues, but besides the rather dark tail in this individual seen in Hanstholm Harbour 29 March 2013, it obviously lacks a more uniformly coloured lower hindneck, mantle and underparts. Nevertheless, I am sure we will get American Herring Gull sooner or later. Here are a couple of examples of other dark-tailed European Herring Gulls photographed in Norway, Scotland, Scotland, Scotland, Scotland and Denmark.

Tuesday, 2 April 2013

argentatus or smithsonianus Herring Gull in Hansholm Harbour


Based on the sequence of 600 positions of the cytochrome B gene, obtained from the feathers of the bird, we can exclude the possibility that it belongs to a member of the Beringian clade, i.e. any large gull breeding in the America’s. Therewith, smithsonianus, as far as mtDNA is concerned, can be excluded.

We found 100 % matches to a number of argentatus argentatus and argentatus argenteus individuals in our own archive of > 1000 sequences. Please note that thus far we have never seen a bird with a smithsonianus-like mtDNA outside North America and that we have never seen a smithsonianus sampled in North America with an mtDNA sequence suggestive of a European origin bird.

In order to get a possibly more refined indication we will sequence the full cytB gene and other genes, but will only do so when we have a sufficiently large batch to do so efficiently. This will not result in a dramatically different answer, but could suggest from which region of the entire argentatus ssp. breeding range it originates. We expect that these data will be available some time in spring next year. Yours,

Peter de Knijff


This gull was initially found by Henrik Haaning Nielsen in December 2012 when its winter plumage displayed extensive dusky grey head streaking and a blotched breast. As the pattern and extent of the head and breast streaking recalled some adult winter plumaged American Herring Gulls, local birders began scrutinized its plumage more careful. Even though it obviously lacked the classic pale cachinnans-like tongue commonly seen on P10 in Newfoundland populations of American Herring Gull, other characters were clearly within variation of smithsonianus.

However, even though several adult smithsonianus outside of Newfoundland show only a short tongue on P10, we can apparently not yet tell such birds from European Herring Gulls with certainty unless we apply DNA technology. If a long pale tongue is not present on P10, identification based on field characters alone will not normally be possible as illustrated by others who have tried claiming an adult smithsonianus on the basis of jizz and the P5-6-7 pattern, but where DNA research proved them wrong as seen here and here.

The strong head streaking in the Hanstholm Gull, reaching well down onto hindneck and breast, was retained well in to late January 2013 as seen here and here. But when I was in Hanstholm Harbour on 28-29 March, the gull had acquired its full breeding plumage. Nevertheless, it was still rather distinct and easy to locate due to its extensive black markings in the primaries, significantly small white apical spots at the primary tips, some slight smudging around the eyes and finally its heavy structure and pale upperparts.

To test the validity of other characters such as jizz and the pattern on P5-6-7, but also in the vain hope that it was in fact a smithsonianus, the local birders followed it around for days during the winter before they finally succeed both in sampling a few droppings and a feather for DNA analysis. The latter has already been shipped off to Peter de Knijff in Holland for sequencing and we all await the result with anticipation. No matter what result will tell, we all expect to learn from this experience.

The primaries show veru small white spots at the tips, notice the black band between the mirror on the underside of P10 and the white tip spot.

The bill has become deep orange-yellow with large red Gonys spot; the eye is very pale yellow with bold yellowish orbital ring. Note that left eye has some dark peppering in the upper half which is missing on the right side.

This flight shot shows the primary pattern well: The large white mirror on P10 is separated from the white tip by a black band. A white mirror spot is visible only on the inner web of P9. Note that the black of the band on P6 extends along the outer web as a spur, this is a little unusual in argentatus which typical has a band only P6 pattern. P5 has a slight 'W' shaped black mark extending across the feather.

Note the small diamond shaped white apical spot in the exposed primaries and the quite long winged look.