Wednesday, 9 July 2014

Iceland Gull, 3cy, 08.01.2012, Blåvandshuk, Blåvand

Date: 2012-01-08
Site: Blåvandhuk, Denmark
Observer: *Henrik Brandt, *Per Poulsen

Date: 8.1.2012. Foto: Henrik Brandt
Date: 8.1.2012. Foto: Per Poulsen
Date: 8.1.2012. Foto: Per Poulsen
Date: 8.1.2012. Foto: Per Poulsen

Kumlien's Gull (Larus [glaucoides] kumlieni), 4cy, 14.01.2012, Hanstholm Harbour, Hanstholm

Case: 2012-248
Date: 2012-01-14
Site: Hanstholm Harbour, Denmark
Observer: *Troells Melgaard, Klaus Malling Olsen m.fl.

Date: 14.1.2012. Foto: Klaus Malling Olsen
Date: 14.1.2012. Foto: Klaus Malling Olsen

Iceland Gull, 3cy, 10-11.01.2012, Hanstholm Slamdepot

Date: 2012-01-10 -(01.11)
Site: Hanstholm Slamdepot, Denmark
Observer: John Kyed, *Peter Hedegaard Kristensen, Henrik Haaning Nielsen m.fl.

Other photo here, here and here. Remember to click on the photos to see the flying bird in large versions.

Date: 10.1.2012. Foto: John Kyed
Date: 10.1.2012. Foto: John Kyed
Date: 11.1.2012. Foto: Henrik Haaning Nielsen
Date: 11.1.2012. Foto: Henrik Haaning Nielsen

The record influx of Kumlien’s Gulls in Denmark

This post is still under construction, but the intension is to provide some overview which can assist the Nordic Rarities Committees in their future assessment of kumlieni claims in Scandinavia.

A selection of the large influx of Kumlien's/Iceland Gull-types in Denmark during the winter 2011-2012 has been categorized into different groups below according to current identification criteria. Because there is still too much uncertainty about the variation in glaucoides, a rather conservative line has been applied.


Kumlien's Gulls which Rarities Committees should accept:

These have been identified as Kumlien’s Gulls because they have either subtle dark shading on the outer webs of at least p6-p10; or a faint 'ghost mirror' on P10; faint dark shading on p6-p9 reaching the primary tips or sub-terminal bands on the outer primaries. The dark shading on outer primaries of immature individuals is as least as dark as the shading on primary coverts and the outer primaries are not paler than the inner primaries.

#1.1: 3cy, 13.1-26.2.2012, Hirtshals Harbour (Case: 2013-168)

#1.2: 3cy, 23.01-03.03.2012, Thyborøn Harbour (Case: 2013-169)

#1.3: 4cy, 8.1-3.3.2012, Hanstholm Harbour (Case: 2013-34)

#1.4: 4cy, 11.1-19.2.2012, Hanstholm Harbour (Case: 2013-171)

#1.5: 4cy, 13.01.2012, Blåvandshuk, Blåvand (Case: 2013-174)

#1.6: 4cy, 14.01.2012, Hanstholm Harbour, Hanstholm (Case: 2012-248)

#1.7: 4cy, 15-16.01.2012, Blåvandshuk, Blåvand (Case: 2013-165)

#1.8: 4cy, 21.1-26.2.2012, Hirtshals Harbour (Case: 2013-35)

#1.9: 4cy, 28.01.2012, Thorsminde Harbour (Case: 2013-164)

#1.10: 4cy, 03.02.2012, Aabenraa Harbour (Case: 2013-167 and 2013-163)

#1.11: ad, 08.01.2012, Blåvandshuk, Blåvand (Case: 2013-85)


Putative Kumlien's Gull which is to be determined

#XX: 4cy, 4.2.2012, Hvide Sande Harbour (Case: 2013-170)


Possible Kumlien's Gulls which Rarities Committees should not accept as they are currently not without doubt

Identification of these examples is not so straightforward. All of these birds may be Kumlien’s Gulls, however it is also possible they are well marked Iceland Gulls. Most individuals have rather dark peppered eyes, light grey marbling on outer webs of outer primaries, some faint pigmentation along the tip of the outer primaries (sub-terminal bands) and some photos give the impression of a diluted version of a “string of pearls”.

#2.1: 3cy, 08.01.2012, Blåvandshuk, Blåvand

#2.2: 3cy, 10.01.2012, Hanstholm Slamdepot

#2.3: 3cy, 13-15.01.2012, Blåvandshuk, Blåvand (Case: 2013-175)

#2.4: 3cy, 14.01.2012, Blåvandshuk, Blåvand (Case: 2013-176)

#2.5: 3cy, 4.2.2012, Hvide Sande Harbour (Case: 2012-247)

#2.6: 3cy, 5.2.2012, Roshage, Hanstholm

#2.7: 4cy, 4.2.2012, Hvide Sande Harbour

#2.8: 4cy, 5.2.2012, Hirtshals Harbour

#2.9: 5cy, 5.2.2012, Hirtshals Harbour

#2.10: 5cy, 5.2.2012, Hirtshals Harbour


Putative Iceland Gull

These gulls which have all been recorded during the record influx of Kumlien’s Gulls are labeled as putative Iceland Gull instead of calling them definite Iceland Gulls. This line was followed because completely white-winged Kumlien’s Gull is claimed to be indistinguishable from glaucoides Iceland Gull.

#3.1: 3cy, 4.2.2012, Hvide Sande Harbour

#3.2: 3cy, 5.2.2012, Hanstholm Harbour

#3.3: 3cy, 5.2.2012, Hanstholm Harbour

#3.4: 3cy, 5.2.2012, Hanstholm Harbour

#3.5: 3cy, 5.2.2012, Hirtshals Harbour

#3.6: 4cy, 4.2.2012, Hvide Sande Harbour

#3.7: 5cy, 4.2.2012, Hvide Sande Harbour

#3.8: 5cy+, 5.2.2012, Hirtshals Harbour


For reference on some of the well describes primary patterns in Kumlien’s Gull please look at the excellent work by Howell and Mactavish (2003). One type which is missing is the one where the outer webs of the outer primaries are not obviously dark pigmented and approach the type A (stage 0) or somewhere between the type A (stage 0) and type B-C (stage 1) except for the presence of faint sub-terminal bands near the tip of at least p8-p9. Sometimes there is the impression of a faint “string of pearls” due to the pigmentation on inner primary webs reach further towards the tip than what I find typical for glaucoides. One could argue that such a primary pattern would fit in right with the type D-F (stage 2) with respect to the sub-terminal primary band, whereas the colouring of the outer webs would fit in between type A (stage 0) and type B-C (stage 1).

In these photos I have sampled individuals showing a primary pattern where slightly darker grey pigmentation can only be discerned on very close range or on high quality flight shots. Note that some individuals only have darker grey on the outer web of P10 whereas on other individuals there are only or additionally some darker grey markings visible at the distal end of the grey tongue on the inner web; i.e. the darker pigmentation runs as a more or less distinct line along the inner edge of grey basal portion of the feather. In the field such birds would most likely appear "white-winged" as the darker grey stripe or pigmentation is only noticeable at certain angles.

The question is whether having dark grey running along the grey tongue and without any dark on the outer web is within pure glaucoides Iceland Gull or if such individuals are in fact pale Kumlien’s Gulls. I believe the latter is the case, but when assign record in Rarities Committees a conservative line should be applied and such individuals should only be accepted if they are documented by high quality photos.

References

Howell, S.N.G. & Mactavish, B. 2003. Identification and variation of winter adult Kumlien's Gulls. Alula 9:2-15.

Kumlien's Gull (Larus [glaucoides] kumlieni), 3cy, 23.01-03.03.2012, Thyborøn Harbour

Case: 2013-169
Date: 2012-01-23 -(03-03)
Site: Thyborøn Harbour, Denmark
Observer: *Henrik Haaning Nielsen, Allan Kjær Villesen m.fl.

Date: 23.1.2012. Foto: Henrik Haaning Nielsen
Date: 23.1.2012. Foto: Henrik Haaning Nielsen
Date: 23.1.2012. Foto: Henrik Haaning
Date: 23.1.2012. Foto: Henrik Haaning
Date: 3.3.2012. Foto: Henrik Haaning Nelsen
Date: 3.3.2012. Foto: Henrik Haaning
Date: 3.3.2012. Foto: Henrik Haaning

Kumlien's Gull (Larus [glaucoides] kumlieni), 4cy, 28.01.2012, Thorsminde Harbour

Case: 2013-164
Date: 2012-01-28
Site: Thorsminde Harbour, Denmark
Observer: *Allan Kjær Villesen, Jørgen Nissen

Date: 28.1.2012. Foto: Allan Kjær Villesen
Date: 28.1.2012. Foto: Allan Kjær Villesen
Date: 28.1.2012. Foto: Allan Kjær Villesen
Date: 28.1.2012. Foto: Jørgen Nissen
Date: 28.1.2012. Foto: Jørgen Nissen
Date: 28.1.2012. Foto: Jørgen Nissen

Kumlien's Gull (Larus [glaucoides] kumlieni), ad, 08.01.2012, Blåvandshuk, Blåvand

Case: 2013-85
Date: 2012-01-08
Site: Blåvandhuk, Denmark
Observer: *Henrik Brandt, Per Poulsen

Date: 8.1.2012. Foto: Per Poulsen
Date: 8.1.2012. Foto: Henrik Brandt

Tuesday, 8 July 2014

Kumlien's Gull (Larus [glaucoides] kumlieni), 4cy, 15-16.01.2012, Blåvandshuk, Blåvand

Case: 2013-165
Date: 2012-01-15 -(01-16)
Site: Blåvandshuk, Denmark
Observer: *Henrik Knudsen, Klaus Malling Olsen, Per Poulsen, Freddy S. Hansen m.fl.

Date: 15.1.2012. Foto: Henrik Knudsen
Date: 15.1.2012. Foto: Henrik Knudsen
Date: 15.1.2012. Foto: Klaus Malling Olsen
Date: 15.1.2012. Foto: Klaus Malling Olsen
Date: 16.1.2012. Foto: Per Poulsen
Date: 16.1.2012. Foto: Per Poulsen

Kumlien's Gull (Larus [glaucoides] kumlieni), 4cy, 03.02.2012, Aabenraa Harbour

Case: 2013-167 (also 2013-163)
Date: 2012-02-03
Site: Aabenraa Harbour, Denmark
Observer: *Clemens Portofeé, Martin Gottschling

Date: 3.2.2012. Foto: Martin Gottschling
Date: 3.2.2012. Foto: Martin Gottschling

Putative Kumlien's Gull (Larus [glaucoides] kumlieni), 4cy, 13.01.2012, Blåvandshuk, Blåvand

Case: 2013-174
Date: 2012-01-13
Site: Blåvandhuk, Denmark
Observer: *Henrik Böhmer, Henrik Knudsen m.fl.

Date: 13.1.2012. Foto: Henrik Böhmer
Date: 13.1.2012. Foto: Henrik Böhmer
Date: 13.1.2012. Foto: Henrik Knudsen
Date: 13.1.2012. Foto: Henrik Knudsen
Date: 13.1.2012. Foto: Henrik Knudsen
Date: 13.1.2012. Foto: Henrik Knudsen
Date: 13.1.2012. Foto: Henrik Böhmer
Date: 13.1.2012. Foto: Henrik Böhmer
Date: 13.1.2012. Foto: Henrik Böhmer
Date: 13.1.2012. Foto: Henrik Böhmer
Date: 13.1.2012. Foto: Henrik Böhmer
Date: 13.1.2012. Foto: Henrik Böhmer
Date: 13.1.2012. Foto: Henrik Böhmer
Date: 13.1.2012. Foto: Henrik Böhmer
Date: 13.1.2012. Foto: Henrik Böhmer
Date: 13.1.2012. Foto: Henrik Böhmer

Iceland Gull, 3cy, 13-15.01.2012, Blåvandshuk, Blåvand

Case: 2013-175
Date: 2012-01-13 -(01-15)
Site: Blåvandhuk, Denmark
Observer: Henrik Böhmer, *Henrik Knudsen m.fl.

Date: 13.1.2012. Foto: Henrik Knudsen
Date: 13.1.2012. Foto: Henrik Knudsen
Date: 15.1.2012. Foto: Henrik Knudsen
Date: 15.1.2012. Foto: Henrik Knudsen
Date: 15.1.2012. Foto: Henrik Knudsen