Black Backed Gulls in Iceland (1 Viewer)

Help ID these as Greater or Lesser. Thanks.

http://www.birdforum.net/pp_gallery/data/500/3367BlackBackedGullA-thumb.jpg

http://www.birdforum.net/pp_gallery/data/3000/3367BlackBackedGullC-thumb.jpg

http://www.birdforum.net/pp_gallery/data/3000/3367BlackBackedGullB-thumb.jpg

They are in my gallery, click my name over on the left to see my gallery here.

Here is the big picture on the lone gull
http://www.birdforum.net/pp_gallery/showphoto.php/photo/60815/sort/1/cat/500/page/1

the group
http://www.birdforum.net/pp_gallery/showphoto.php/photo/60817/sort/1/size/medium/cat/500/page/1

The legs of the gull in the single photo look pink, then in the group I see yellow and pink. Do you recall what the leg color was?

The leg color of the single gull was very pale, so I was going for Greater (also by the length of the primaries), but I do not recall the group gulls. They are in a lake right downtown in Reykjavik. Edward can walk by those very gulls any day, I think.

I then changed my mind on the lone gull right in the town and crossed out Greater!

I actually have video of the lone gull as well. I have to copy all my video to view it and have no skills posting video.

The leg color of the single gull was very pale but not exactly yellow..hard to say.

Hi Tero!
I think it´s quite safe to say that the lone gull is a GBBG, even on bill size alone. It is also moulting it´s primaries, which makes the pattern a bit messy and hard to define. GBBG has broad white tipps to p10+9, and there is a hint of that in pic. The "brutal" look of this one, the massive bill, with a bulbous tip, pinkish legs and the small beady eye makes it a GBBG.

In the group, the seven adults are all LBBG. Compare them to the lone GBBG and you´l see! The 7 adult s are a mixture of graellsii and intermedius it looks like, graellsii usually being paler than intermedius when standing together like this, but there are variaton in upperpart colouratin, some intermedius being paler than others and so on. It´s also very difficult to judge upperpart tone in photos, and in real life, you have to have a "long time look"! Among the young birds, juveniles, I´m fairly sure that the one with the spread wings is a LBBG, the others HG.
JanJ

For some reason I cannot view the pictures but it is worth mentioning that the LBB Gulls in Iceland are regarded as all graellsi. I thought I had some intermedius birds there in March though.

Steve

I agree with JanJ. Some of the Lesser Black Backs in the picture look too dark for graellsii and look just like the intermedius I see here in south-west Sweden. It's worth pointing out yet again that the taxonomy of this group is complex and that there are clinal differences. In western Norway, for instance, I've heard reports of mixed pairs between apparent graellsii and intermedius. Heavens knows whether these birds and their offspring are "real" intermedius or graellsii . Maybe we should be thinking instead of "intermaellsii"!

Rgds

Greg

sphinx79 said:

I agree with JanJ. Some of the Lesser Black Backs in the picture look too dark for graellsii and look just like the intermedius I see here in south-west Sweden. It's worth pointing out yet again that the taxonomy of this group is complex and that there are clinal differences. In western Norway, for instance, I've heard reports of mixed pairs between apparent graellsii and intermedius. Heavens knows whether these birds and their offspring are "real" intermedius or graellsii . Maybe we should be thinking instead of "intermaellsii"!

Rgds

Greg

Click to expand...

Intermaellsii, really a good one!
JanJ

I have now been able to look at the pictures in Tero's gallery and there definitely look to be both graellsi and intermedius birds.
LBB Gull is a fairly recent colonist in Iceland and it seems that tw races must be involved.
Interesting comment about mixed pairs in western Norway. Maybe the same applies to Iceland?? I see a whole range of shades between graellsi and jet black fuscus types in Leicestershire, suggesting that the different forms interbreed widely.

Steve

An excellent job by JanJ, Greg and Steve!

Just for the fun of it however, I'm going to tentatively disagree, and suggest the possibiity that there is a Great Black-backed Gull in the middle of the second photo. Consider the size and proportions of the bill compared to all the other gulls in the photo, in combination with the amount of white visible on the primaries. The slope and shape of the head looks a bit more brutish as well, though this would be the weakest and most subjective consideration.

True, a GBBG ought to be towering above the other gulls, but a small female hunkered down might explain that. My other concern is that mantle color ought to be distinctly darker than the LBBGs, so it is a theory, but I find the large thick bill / prominently white tipped primaries combination to be worth... discussing! :bounce:

Thanks. I am still having a bit of a hard time with these. Saw so many that at first I ignored them, as they were a bit far.

Hmm, you mean the image with the stairs visible. I didn´t even look at that image before now, and it looks like your right there.
JanJ

LBBG in Iceland

Hi folks,

It is very interesting to look at LBBG in Iceland, and one can really see big variations in the grey colour on occasions.

From these photos it is very difficult to say if we are really looking at a colour variation or not. The quality is way to low to be certain, and I've often noticed that when birds turn slightly around the colour will change and the grey will then look darker or paler. It is really amazing how it can change depending on the angle toward the light source !

But sometimes we notice really darker birds, as when I was birding with Steve and Edward last March. Then we saw four birds together, take a look here... http://www.hi.is/~yannk/myndir/gulls/yk_larfus280305.jpg

Officially it is only graellsii that breeds in Iceland, and our population probably originated from the UK in the late 20's/30's. Today the largest colony counts over 30.000 pairs near the international airport. It is not certain if we have pure intermedius birds breeding here (I think not), although the two dark ones on the above photo may have been such vagrants (we'd just had some SE-winds then). Some say that our birds (at least some of them) may belong to the "Dutch type" which corresponds to the breeding populations between graellsii and intermedius, which were first found in the Netherlands but are now more widespread (reaching northern France).

In other words, this is a difficult subject, made even more difficult by the light and colour variations and colour actually given by the digital cameras. I guess DNA is the thing needed here to be really certain.... We can always say "this is probably an intermedius" but saying "this is an intermedius" is like being a cow walking on ice (like we say in icelandic).

And by the way, the lone gull is certainly a GBBG !
Cheers, Yann

Hi Yann!
I agree, and in reality this means that it´s not advisable to judge any photo in these matters with certainty. It also is a well known fact in the field as you describe it.
Nice image, graellsii and intermedius?
JanJ