Yellow-legged Gull on British list (1 Viewer)

[Rhion]

I've just been told that Yellow-legged Gull has been split as a species (Larus cachinnans) by the BOURC. I don't remember seeing any announcement about this though. Can anybody confirm it?

 

[postcardcv]

I don't think it's happened yet - I certainly can't find anything on the bou website about it and there has been no mention of it on birdguides either. Whilst I'm sure they will eventually split out both yellow-legged and Caspian I think it will be a while yet.

 

[Bluetail]

If a split was imminent wouldn't they have announced it at the same time as the Black Scoter split?

 

[Docmartin]

I think the confusion is that Caspian Gull was added to the British List (as L. argentatus cachinnans) last year, but there has not been a split.

 

[Rhion]

That would seem to settle it - thanks.

And the information came from an observatory [which shall remain nameless] warden too. Tsk, tsk!

 

[Lucky Birder]

The science is clear and cachinnans and michaellis will be split.

 

[Edward woodwood]

there is still some confusion over limits in cachinnans

to expand:

some authors (mostly eastern Europeans/Russians) are of the opinion that south eastern Herrings intergrade with cachs in a broad zone...

Tim

 

[Allen S. Moore]

Yellow-legged Gull as a species

there is still some confusion over limits in cachinnans

I must admit that I thought that it was split from herring gull years ago. I see it in its "split" name in Spanish ornithological literature. Although I have not bought "British Birds" for several years, there was a lengthy paper about gulls a few years ago which, if I remember correctly, was explaining the taxonomy of herring gulls and their close relatives. The paper sticks in the memory as the authors argued against the existence of "omissus" as a sub-species of herring gull, and I had identified one here on the Isle of Man, as had another very careful birder.
Allen

 

[Edward woodwood]

Hi Allen

the debate is ongoing

see AERC TAC's taxonomic recommendations of Dec 2003

there was a bit of a ding-dong between chalyrecki (spelling incorrect) and others about taxonomy of Herring Gulls in the 90s

Tim

 

[Allen S. Moore]

Hi Allen

the debate is ongoing

see AERC TAC's taxonomic recommendations of Dec 2003

there was a bit of a ding-dong between chalyrecki (spelling incorrect) and others about taxonomy of Herring Gulls in the 90s

Tim

Thanks.
Seeing your picture of John Lydon, presumably a link to punk / new wave, and your knowledge of gulls, did you like the photos on the covers of Echo and the Bunnymen's discs 'A Promise' (single) and 'Heaven Up Here' (CD)?
Allen

 

[Edward woodwood]

Yep Allen Heaven Up Here's a great record

was never to keen on a Flock of Seagulls though...

you can get the AERC stuff on the net for free - it's excellent

http://www.aerc.be/aerc_tac.htm

 

[Docmartin]

there is still some confusion over limits in cachinnans

to expand:

some authors (mostly eastern Europeans/Russians) are of the opinion that south eastern Herrings intergrade with cachs in a broad zone...

Tim

Actually.. cachinnans DOES intergrade with argentatus, and probably has done, at least sporadically, for a while. It's reasonable to believe that omissus arose from introgression of cachinnans into an eastern population of argentatus, although the published evidence (Helbig and Crochet papers) would suggest that there is little if any evidence of cachinnans mtDNA in argentatus.

 

[Allen S. Moore]

Yep Allen Heaven Up Here's a great record

was never to keen on a Flock of Seagulls though...

you can get the AERC stuff on the net for free - it's excellent

http://www.aerc.be/aerc_tac.htm

Well, I thought that their "Messages from the Rings of Saturn" was out of this world!
Allen

 

[sphinx79]

Actually.. cachinnans DOES intergrade with argentatus, and probably has done, at least sporadically, for a while. It's reasonable to believe that omissus arose from introgression of cachinnans into an eastern population of argentatus, although the published evidence (Helbig and Crochet papers) would suggest that there is little if any evidence of cachinnans mtDNA in argentatus.

Yes, cachinnans hybridises with argentatus, as does michahellis but this is to be expected where similar species meet and in any case isn't a bar to species status.

Many more similar species, e.g. Collared/Pied Flycatcher, Carrion/Hooded Crow, to name just a couple, hybridise freely in overlap zones. The thing about cachinnans is that it is so different morphologically from any of the western herring gull types that it's impossible (for me anyway) to imagine it not being a good species.

Without knowing much about the science behind it, the argument that omissus arose from intergradation between eastern argentatus and cachinnans strikes me as fanciful to put it mildly. It's well established nowadays that omissus is merely a variant of argentatus with yellow legs and not a separate form. And you have to ask how on earth Herring Gulls with yellow legs would arise from hybridisation between argentatus and cachinnans, both of which have pink legs...

Rgds

Greg

 

[Docmartin]

Without knowing much about the science behind it, the argument that omissus arose from intergradation between eastern argentatus and cachinnans strikes me as fanciful to put it mildly. It's well established nowadays that omissus is merely a variant of argentatus with yellow legs and not a separate form.

It may be well established among the chattering classes of Western Europe's gull elite, who perpetuate an oral tradition within which any old rubbish about gulls may be accepted as gospel... (that's a joke, btw o o o ).... but it is not well established in terms of evidence or the literature. It depends on how you define omissus (which is always the problem with omissus). The primarily yellow-legged 'omissus' Herring Gulls that breed in inland colonies in North-eastern Europe were regarded by Panov and Monzikov, in one of the very few proper papers on the subject (1999; russ j zool 3, 129-141) as being the result of old invasions of L. cachinnans into eastern Fennoscandia. It's a long way from being the only explanation, but it's plausible rather than fanciful.

And you have to ask how on earth Herring Gulls with yellow legs would arise from hybridisation between argentatus and cachinnans, both of which have pink legs...
Greg

Define 'pink'. If you define it in a way that includes 'variably bright yellow to pink', I'll agree.

 

[JANJ]

Yes, cachinnans hybridises with argentatus, as does michahellis but this is to be expected where similar species meet and in any case isn't a bar to species status.

Many more similar species, e.g. Collared/Pied Flycatcher, Carrion/Hooded Crow, to name just a couple, hybridise freely in overlap zones. The thing about cachinnans is that it is so different morphologically from any of the western herring gull types that it's impossible (for me anyway) to imagine it not being a good species.

Without knowing much about the science behind it, the argument that omissus arose from intergradation between eastern argentatus and cachinnans strikes me as fanciful to put it mildly. It's well established nowadays that omissus is merely a variant of argentatus with yellow legs and not a separate form. And you have to ask how on
earth Herring Gulls with yellow legs would arise from hybridisation between argentatus and cachinnans, both of which have pink legs...

Rgds

Greg

Well said, and correctly so!
JanJ

 

[Edward woodwood]

Martin has dealt with those points

offspring can have characters not apparent in the parents

you can see this in every day life

Tim

 

[HH75]

Hi all,
I had heard about introgression (past or present) between cachinnans and argentatus, and also seen barabensis described as possibly being a result of past introgression between heuglini and cachinnans. I also share Martin's confusion over just what 'omissus' actually is/was: apparently, the original designation referred to inland-breeding birds in the Baltic region, some of which had yellow legs, but by no means all, with these birds being 'bred out' following colonisation of the area by 'typical' argentatus (I don't have Jonsson's paper at hand to check that I have my facts straight)?
Of course, interbreeding between various gull taxa generally treated as being seperate species regularly occurs in contact zones where one or the other of the taxa (or both) is scarce, so this doesn't necessarily invalidate the treatment of cachinnans as a full species, even under the BSC, providing that interbreeding does not occur so widely that the taxa are likely to merge?
Harry

 

[Bluetail]

Just a devil's advocate question from someone who doesn't understand genetics, let alone the LWHG complex: Is the mtDNA of omissus distinguishable from argentatus? Is there any chance that omissus could be a good (sub)species that is heading for extinction because of inability to compete with argentatus?

 

[Docmartin]

Just a devil's advocate question from someone who doesn't understand genetics, let alone the LWHG complex: Is the mtDNA of omissus distinguishable from argentatus? Is there any chance that omissus could be a good (sub)species that is heading for extinction because of inability to compete with argentatus?

First, define omissus.... but there is, as far as I can see, no genetically distinct population of omissus 'Marsh Gull'. But the suggestion that it is/was a valid subspecies which has been/is being lost because of expansion of argentatus, is not a new one.