Could perhaps a kumlieni (stage 4 /Howell & Mactavish 2003) be considered? Pattern could fit such an individual well (where the dark markings as deep black as it seems to be on the pic? Structure, pale eye, lack of dark marking on p5 and dark tipped p10 in combination (not in all thayeri)would perhaps do the trick. More of this bird here
Thanks for your comments, Jan.
As you have seen I've been writting a little about the bird on my blog (birdingfaroes.wordpress.com).
I was lucky enough to see this bird today. The dark colour on the primaries really is solid black. Perhaps the dark colour on p10 was a little bit paler, but generally it was really solid black - the images do not cheat in this respect.
This is not a classic Thayer's Gull. You point to the fact that it lacks black in p5. It would be very good if it had black on p5, but according to "Gulls" by Olsen and Larsson 25 % of all Thayer's Gulls do not show dark on p5.
You also mention the pale eye. According to Olsen and Larsson 10 % of all Thayer's Gulls do have a pale iris.
But yes, the structure felt more like a very heavy Iceland Gull than a Herring Gull - but it was in deed somewhat intermediate. This being said I've never seen an accepted Thayer's Gull, so I do not know the jizz.
Bottom line is that it's not a classic Thayer's Gull, and therefore this bird is on the egde of representing the palest possible Thayer's and the darkest possible Kumlien's...
But comments from people with experience of kumlieni vs thayeri would be much appreciated.
The markings on p10 was a litle bit lighter, this photo does showe that clearly, but i belive that that do occure in some Thayer´s gulls, Silas´es photos do make the bird look ligther than it realy is.
Lack of marking on p5 should not be an issue when it´s known that this does occure in 3/4 of the Thayer´s population, and bare in mind that the markings is variable on Thayer´s Gulls, this bird i belive does lay within this variation, the yelowish iris does nigther create a problem, David Sibley as Klaus Malling also do mention that 10% of the population showes pale iris.
I strongly dissagre when Silas sayes that this bird is on the egde of representing the palest Thayer´s Gulls or the darkest Kumlien´s Guls, the darknes of the markings clearly is well on the Thayer´s side, but as i wrote in the title/info this showes a bird with minimal dark markings !! The leg color is raspery pink and defentiy what a Thayer´s Gulls shows.
Sorry, lack of black markings does occore in 1/4 of the population i should have wrote. ;-)
As Silas & Rodmund (and myself above), mentioned not all thayeri have dark markings on p5 and iris colour varies.
The primaries of thayeri is more of slaty blackish (KGS 14,5-17 Gulls (outer web darkest), while on kumlieni slaty grey (commonly KGS 7-10, Howell & Dunn) while Gulls gives 8-9 (on darkest birds 12-13)
One should probably not go there - a possible thayeri x kumlieni?
No doubt that the quality of the black in primaries is darker than in most Kumliens, which tend to be greyer than this. But Kumlien's Gulls can show black markings.
The structure is more like a Iceland Gulls than a Herring Gull. Head and bill are not quite heavy enough for a typical Thayer's. It does not have a full black sub terminal bar on p6 and it looks too pale for a Thayer's.
So yes, the quality of the black in the primaries do point towards Thayer's Gull but pretty much all other features point to Kumlien's Gull.
Leg colours are really difficult to jugde by as they differ significantly from individual to individual.
In Gulls by P.J Grant page 316 pic 439 you can see a Kumlieni like this
And here you can see a Adult Thayer´s Gull simular to the bird in discustion, accepted by the Irish rarity commety, http://www.irbc.ie/announcements/announce28.php The only slight difrent you can see on the third photo is the subterminalband on p6, and do note that the bird showe a pale iris in that photo too.
In my opinion , the Irish bird have a more Herringgull-like bill and head.
It is posible that the irish bird have a more Herring Gull like bill and head, but this can be because the Irish bird is a male Thayer´s and the Faroese bird is a female, female Thayer´s Gulls does have a rounder shaped head and smaler/slimmer bill.
|Nye kommentarer til dette billede er ikke muligt.|
|Bemærk: at alle billeder har copyright og må ikke anvendes uden accept fra den respektive fotograf.|