Monday, 22 September 2014

Kumlien’s Gull in Norway during the record influx in 2012

The Norwegian Rarities Committee (NSKF) has recently accepted seven records of Kumlien’s Gull from the major influx during the winter 2011-2012. However, note that not all claims have yet been submitted and the actual number of Kumlien's Gull in Norway during the influx may thus be higher.

Photos of the seven accepted records can be found in the links below:


ØSTFOLD:

4K Utgårdskilen, Vesterøy, Hvaler 8.-12.2* (F) (R. G. Bosy mfl.).

See photos here: 10.2.2012, 10.2.2012, 10.2.2012, 10.2.2012, 10.2.2012, 10.2.2012, 11.2.2012, 11.2.2012, 11.2.2012, 11.2.2012, 11.2.2012, 11.2.2012, 11.2.2012, 12.2.2012, 12.2.2012, 12.2.2012, 12.2.2012 and 12.2.2012.



TELEMARK:

Ad. Langesund, Bamble 21.1-23.2* (F) (*Ø. W. Johannessen mfl.).

See photos here: 18.1.2012, 18.1.2012, 18.1.2012 and 21.1.2012.



ROGALAND:

4K Ølberg havn, Sola 24.-27.1* (F) (E. Ween mfl.).

See photo here: 24.1.2012.



SØR-TRØNDELAG:

4K Gaulosen og Buvika, Melhus og Skaun 14.-28.1* (F) (*T. Bollingmo mfl.).

See photos here: 14.1.2012, 15.1.2012, 15.1.2012, 22.1.2012, 22.1.2012, and 22.1.2012.



4K Nidarø, Trondheim 15.-28.1* (F) (O. Heggøy, A. Winnem mfl.).

See photos here: 15.1.2012, 15.1.2012, 15.1.2012, 15.1.2012, 15.1.2012, 15.1.2012, 15.1.2012, 15.1.2012, 15.1.2012, 15.1.2012, 15.1.2012, 16.1.2012, 16.1.2012, 16.1.2012, 16.1.2012, 18.1.2012, 18.1.2012, 22.1.2012, 23.1.2012 and 23.1.2012.



NORDLAND:

4K Glea, Røstlandet, Røst 16.1* (F) (S. Baines).

See photos here: 16.1.2012, 16.1.2012 and 16.1.2012.



4K Glea, Røstlandet, Røst 6.2* (F) (S. Baines).

See photo from: 6.2.2012.

Monday, 15 September 2014

Herring Gull (Larus argentatus) with reduced pigmentation seen in Grenaa Harbour

Some of these pale type Herring Gulls can recall birds labelled as hybrid hyperboreus x argentatus (Viking Gull), but as this individual lacks a clear influence from Glaucous Gull when it comes to the pattern on each feather, is is considered to be European Herring Gulls with reduced or aberrant pigmentation.

Caspian Gull (Larus cachinnans), 1cy, 14.9.2014, Grenaa Harbour














As highlighted by Lou Bertalan please note that the P5 in right wing is pale and looks like a 2nd generation feather.

Note that the pale P5 in right looks like a 2nd generation feather. S1 in left wing is pale greyish in a similar way

Caspian Gull (Larus cachinnans), 4cy, 14.9.2014, Grenaa Harbour

This could be a pure cachinnans and even though one may argue that most of the features seen in this bird also fit argentatus, there are firm clues that at least one of the parents must have been a cachinnans. Even though the upperparts are rather pale; iris rather pale; head relatively striated; and the black band on P5 rather narrow, it would not surprise me if it still fits within the phenotypic variation found in true cachinnans. However, a hybrid or backcross is not easy to rule out.

The winter streaks in head are needle-thin and very distinctive without the typical coarse spotted argentatus appearance; cachinnans can have such streaks in autumn as also seen on Netfugl.

Characters in favor of cachinnans are e.g. the relative and thin long legs compared to the adjacent Herring Gulls, a bill which is relative slim without pronounced gonys angle, a dark red orbital ring, reminiscence of a cachinnans neck boa with dark spots on lower neck, and upperparts which are marginally darker than on nearby argentatus.


















Wednesday, 9 July 2014

Iceland Gull (Larus glaucoides), 3cy, 08.01.2012, Blåvandshuk, Blåvand

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

It is considered to be an Iceland Gull (Larus glaucoides) though this is not to say it is not a Kumlien's Gull. It has without doubt some faint pigmentation along the tip of the outer primaries. However, note that it is not abnormal for 2nd- and, especially, 3rd-cycle glaucoides to show a brown wash on the outer primaries. The plumage of these immature gulls often looks quite retarded, with still lots of brown in the wing. Note that the brown wash on outer primaries of such birds simply matches the brown wash on outer secondaries, as is often the case in other 3rd-cycle gulls (e.g. Herring Gull). It is just a trait of immature plumage.

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, 09.01-05.03.2012, Hanstholm Harbour, Hanstholm

Case: 2012-248
Date: 2012-01-09 -(03-05)
Site: Hanstholm Harbour, Denmark
Observer: Troells Melgaard, Klaus Malling Olsen, Henrik Haaning Nielsen m.fl.

This individual has been identified as Kumlien’s Gulls based on its primary pattern. Note that there is subtle dark shading on the outer webs of the outer four primaries with the colour being darker on the outer than on the inner web. Moreover, the dark shading on P7-P9 reaches the primary tips where the dark colour creates a back-curving hook onto the inner webs which is considered to be a significant kumlieni character. As is often the case with immature Kumlien’s Gulls, the dark colour is often darkest at the very tip of the primaries and also half way out on the outer web. Another very important character is the faint 'ghost mirror' on P10 combined with a dark sub-terminal pattern.

Note that the dark shading on the outer primaries is darker than the shading on the inner primaries and the primary coverts. Additionally, the outer primaries are also darker than the secondaries. The combination of the pseudo-mirror on P10 and dark subterminal spots, dark outer webs on the outer primaries and dark pattern forming a hook onto the inner webs should exclude the brown-winged glaucoides known from West Greenland and Iceland

Date: 14.1.2012. Foto: Klaus Malling Olsen
Date: 14.1.2012. Foto: Klaus Malling Olsen
Date: 14.1.2012. Foto: Klaus Malling Olsen
Date: 14.1.2012. Foto: Klaus Malling Olsen
Date: 14.1.2012. Foto: Klaus Malling Olsen
Date: 14.1.2012. Foto: Klaus Malling Olsen
Date: 14.1.2012. Foto: Klaus Malling Olsen
Date: 14.1.2012. Foto: Klaus Malling Olsen
Date: 14.1.2012. Foto: Lars Paaby
Date: 14.1.2012. Foto: Lars Paaby
Date: 14.1.2012. Foto: Lars Paaby
Date: x.x.2012. Foto: Henrik Haaning Nielsen
Date: x.x.2012. Foto: Henrik Haaning Nielsen

Iceland Gull (Larus glaucoides), 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.

It is considered to be an Iceland Gull (Larus glaucoides) though this is not to say that it could not be a Kumlien's Gull. It has without doubt some faint pigmentation along the tip of the outer primaries. However, note that it is not abnormal for 2nd- and, especially, 3rd-cycle glaucoides to show a brown wash on the outer primaries. The plumage of these immature gulls often looks quite retarded, with still lots of brown in the wing. Note that the brown wash on outer primaries of such birds simply matches the brown wash on outer secondaries, as is often the case in other 3rd-cycle gulls (e.g. Herring Gull). It is just a trait of immature plumage.

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
Date: 28.1.2012. Foto: John Kyed
Date: 28.1.2012. Foto: John Kyed
Date: 28.1.2012. Foto: John Kyed

The record influx of Kumlien’s Gulls in Denmark

NOTE THAT THIS POST IS STILL UNDER CONSTRUCTION

The intention with this post is to provide some overview which can assist the Nordic Rarities Committees in their future assessment of kumlieni claims in Scandinavia.

A selection of individuals from the large influx of Kumlien's/Iceland Gull-types in Denmark during the winter 2011-2012 have 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.


Typical examples which Rarities Committees should accept

These individuals have all been identified as Kumlien’s Gulls based on their primary pattern. They have subtle dark shading on the outer webs of the outer primaries with the colour being darker on the outer than on the inner web. Moreover, the dark shading on P6-P9 reaches the primary tips where the dark colour penetrates onto the inner web and thus creates a back-curving hook which is considered to be a significant kumlieni character. The dark colour is often darkest at the very tip of the feather and half way out on the outer web. Some individuals also have a faint 'ghost mirror' on P10 and sub-terminal bands on the other outer primaries.

Note that the dark shading on the outer primaries of especially second winter individuals is darker than the shading on the primary coverts and the inner primaries. Additionally, the outer primaries are darker or at least not paler than the secondaries.

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

#1.2: 4cy, 8.1-3.3.2012, Hanstholm Harbour (Case: 2013-34) - kumlieni

#1.3: 4cy, 9.1-5.3.2012, Hanstholm Harbour (Case: 2012-248) - kumlieni

#1.4: 4cy, 21.1-26.2.2012, Hirtshals Harbour (Case: 2013-35) - kumlieni

#1.5: 4cy+, 8.1.2012, Blåvandshuk, Blåvand (Case: 2013-85) - kumlieni


Problematic birds which are currently not without doubt

Identifications of these examples are not so straightforward. All of these individuals may be Kumlien’s Gulls; however, for several of them it does not seem safe to exclude well-marked Iceland Gulls and for some individuals the latter solution actually seems like the most plausible.

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”.

However, it is important to note that it is not abnormal for 2nd- and, especially, 3rd-cycle glaucoides to show a brown wash on the outer primaries. The plumage of such well-marked immature gulls is known often to look quite retarded, with still lots of brown in the wing, and where the brown wash on the outer primaries of such birds simply matches the brown wash on outer secondaries, as is often the case in other 3rd-cycle gulls (e.g. Herring Gull). It could thus be considered just to be a trait of immature plumage rather than a clear indication of Kumlien’s Gull.

#2.1: 3cy, 23.1-3.3.2012, Thyborøn Harbour (Case: 2013-169) - kumlieni?

#2.2: 4cy, 11.1-19.2.2012, Hanstholm Harbour (Case: 2013-171) - kumlieni?

#2.3: 4cy, 13.1.2012, Blåvandshuk, Blåvand (Case: 2013-174) - kumlieni?

#2.4: 4cy, 15-16.1.2012, Blåvandshuk, Blåvand (Case: 2013-165) - kumlieni?

#2.5: 4cy, 28.1.2012, Thorsminde Harbour (Case: 2013-164) - kumlieni?

#2.6: 4cy, 3.2.2012, Aabenraa Harbour (Case: 2013-167 and 2013-163) - kumlieni?

#2.7: 4cy, 4.2.2012, Hvide Sande Harbour (Case: 2013-170) - kumlieni?

#2.8: 4cy, 5.2.2012, Hirtshals Harbour - kumlieni?

#2.9: 4cy+ 5.2.2012, Hirtshals Harbour - kumlieni?

#2.10: 4cy+, 5.2.2012, Hirtshals Harbour - kumlieni?


Iceland Gulls as a reference

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.

#2.1: 3cy, 8.1.2012, Blåvandshuk, Blåvand - glaucoides

#2.2: 3cy, 10.1.2012, Hanstholm Slamdepot - glaucoides

#2.3: 3cy, 13-15.1.2012, Blåvandshuk, Blåvand (Case: 2013-175) - glaucoides

#2.4: 3cy, 14.1.2012, Blåvandshuk, Blåvand (Case: 2013-176) - glaucoides

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

#2.6: 3cy, 4.2.2012, Hvide Sande Harbour - glaucoides

#2.7: 3cy, 5.2.2012, Hanstholm Harbour - glaucoides

#2.8: 3cy, 5.2.2012, Hanstholm Harbour - glaucoides

#2.9: 3cy, 5.2.2012, Hanstholm Harbour - glaucoides

#2.10: 3cy, 5.2.2012, Roshage, Hanstholm - glaucoides

#2.11: 3cy, 5.2.2012, Hirtshals Harbour - glaucoides

#2.12: 4cy, 4.2.2012, Hvide Sande Harbour - glaucoides

#2.13: 4cy, 4.2.2012, Hvide Sande Harbour - glaucoides

#2.14: 5cy, 4.2.2012, Hvide Sande Harbour - glaucoides

#2.15: 5cy+, 5.2.2012, Hirtshals Harbour - glaucoides


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.

Possible 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.

From these photos alone it seems not safe to exclude a well-marked Iceland Gull (Larus glaucoides) though this is not to say it is not Kumlien's Gulls. It has without doubt some dark shading on the outer webs of the outer primaries with the colour being darker on the outer than on the inner web, but the flight shots do not seem to show a clear Kumlien's/Thayer's pattern on the outer. Even though the dark shading on P7-P9 reaches the primary tips, the dark pattern does not seem to penetrate onto the inner web, i.e. the bird seems to lack the dark hook-pattern on the inner web. It is also difficult to determine whether there is a faint 'ghost mirror' on P10. This could be caused by the state of the plumage which seems to be rather bleached and especially so on the last photos which were taken in March. As a result it does not seem safe to exclude a well-marked glaucoides.

Note that it is not abnormal for 2nd- and, especially, 3rd-cycle glaucoides to show a brown wash on the outer primaries. The plumage of such well-marked immature gulls often looks quite retarded, with still lots of brown in the wing. Note that the brown wash on outer primaries of such birds simply matches the brown wash on outer secondaries, as is often the case in other 3rd-cycle gulls (e.g. Herring Gull). It is therefore considered just to be a trait of immature plumage.

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 Nielsen
Date: 3.3.2012. Foto: Henrik Haaning Nielsen
Date: 3.3.2012. Foto: Henrik Haaning Nielsen
Date: 3.3.2012. Foto: Rune Sø Neergaard
Date: 3.3.2012. Foto: Rune Sø Neergaard
Date: 3.3.2012. Foto: Rune Sø Neergaard
Date: 3.3.2012. Foto: Rune Sø Neergaard
Date: 3.3.2012. Foto: Rune Sø Neergaard