Gull ID help please. Cambridgeshire, UK (1 Viewer)

[Milan]

Hi fellow bird enthusiasts.

I noticed this gull on a partially flooded (and frozen) meadow just on the edge of Cambridge (UK) this morning. This one attracted my attention as it landed, briefly, not far away from a small group of black headed gulls. Based on the overall appearance I initially thought it might be Common Gull however after closer inspection of the image I made I'm leaning toward Ring-billed gull (colour of legs, light coloured iris). I'm not an gull ID expert so any comments and help with ID would be appreciated.

Thank You in advance.

 

[Deb Burhinus]

Hi it’s a Common Gull

The iris is obscured by a reed (but some Common Gull can have a pale iris) - the bill is slim too and note the indistinct pattern of the bill band compare

https://gullstothehorizon.files.wordpress.com/2014/03/delawarensis-canus-adult-portraits1.jpg

 

[lou salomon]

it's a nominate canus Common Gull on wingpattern. i noticed a high degree of ind. with paler iris in wintering common gulls in eastern europe this winter which hints towards a larger percentage of wintering ssp. heinei (russian common gull), but of course a paler iris can be shown by european birds too.

 

[Deb Burhinus]

Hi Lou

Do you have a visual reference link please that shows the comparative wing pattern in nominate and heinei - are you referring to moult timing patterns vis a vis the time of year or do they actually differ?

 

[lou salomon]

there is a sophisticated scoring system for identification of all subspecies of Larus canus, created by top gullers Peter Adriaens and Chris Gibbins published in Dutch Birding four years ago. Generally, heinei in winter have brighter bare parts, less head striation (just a necklace), longer wings (hard to tell in the field), and more black in wing, black often reaching p4, with p9 mirror being smaller (same length as black tip), inner web to p8 reaching primary coverts and p6-p7 lacking obvious/broad pale "moons" (=whitish marks between grey bases and black subterminal marks). that's about what i recall of the differences, but there's a lot of overlap (thus the scoring system) and intergrades seem to be common. i have no direct comparison material. the article is here:
http://gull-research.org/papers/pap...S2FlNtFNdqgZ1tSfXazjikWrcAOMGuMMdkDFQWPlgFyfY

or if you don't like to read for days, this is an older one from 2016 concerning identification of ssp. heinei in a scottish context : http://gull-research.org/papers/papers9/Gulls_SB36(1) 2016 heinei Common Gulls.pdf?fbclid=IwAR3OQssElyzwKnvr7xOGf6yn0H42Cpo23J4hkNB4D6Fu2uM5hGenhLw5WDE

 

[Deb Burhinus]

Thanks Lou - so re. ‘wingpattern’ large mirrors on 8-6 in OP ?

 

[lou salomon]

there's no mirrors on p6-7, just occasionally on p8 in Common Gull. don't get the question really.
mirrors are on p9 and 10, and yes, they are large as in nominate canus. also note lack of any p5 mark which readily excludes a russian heinei.

 

[Deb Burhinus]

sorry I meant white ‘tips’ not ‘mirrors’ 🤪 I was comparing these two in thevlink you gave me (2nd)(but beginning to wish I hadn’t asked 😂)

http://gull-research.org/papers/papers9/Gulls_SB36(1)%202016%20heinei%20Common%20%20%20Gulls.pdf?fbclid=IwAR3OQssElyzwKnvr7xOGf6yn0H42Cpo23J4hkNB4D6Fu2uM5hGenhLw5WDE

 

[lou salomon]

the white tips are there in p6-8, i think their size is of no relevance for subsp. identification. p9 and 10 usually lack a white tip in common gull. actually p9 often has a very small white tip. we're talking about adult birds only, of course.

 

[Milan]

Hi it’s a Common Gull

The iris is obscured by a reed (but some Common Gull can have a pale iris) - the bill is slim too and note the indistinct pattern of the bill band compare

https://gullstothehorizon.files.wordpress.com/2014/03/delawarensis-canus-adult-portraits1.jpg

Thanks Deb. Yes the iris is unfortunately obscured. Thanks for pointing out the bill band pattern as well all useful info for me.👍

 

[Milan]

it's a nominate canus Common Gull on wingpattern. i noticed a high degree of ind. with paler iris in wintering common gulls in eastern europe this winter which hints towards a larger percentage of wintering ssp. heinei (russian common gull), but of course a paler iris can be shown by european birds too.

Thanks Lou. Very interesting!

 

[Deb Burhinus]

Thanks Lou. Very interesting!

It certainly was - But beyond my pay grade as you could probably tell 😂

 

[Milan]

there is a sophisticated scoring system for identification of all subspecies of Larus canus, created by top gullers Peter Adriaens and Chris Gibbins published in Dutch Birding four years ago. Generally, heinei in winter have brighter bare parts, less head striation (just a necklace), longer wings (hard to tell in the field), and more black in wing, black often reaching p4, with p9 mirror being smaller (same length as black tip), inner web to p8 reaching primary coverts and p6-p7 lacking obvious/broad pale "moons" (=whitish marks between grey bases and black subterminal marks). that's about what i recall of the differences, but there's a lot of overlap (thus the scoring system) and intergrades seem to be common. i have no direct comparison material. the article is here:
http://gull-research.org/papers/pap...S2FlNtFNdqgZ1tSfXazjikWrcAOMGuMMdkDFQWPlgFyfY

or if you don't like to read for days, this is an older one from 2016 concerning identification of ssp. heinei in a scottish context : http://gull-research.org/papers/papers9/Gulls_SB36(1) 2016 heinei Common Gulls.pdf?fbclid=IwAR3OQssElyzwKnvr7xOGf6yn0H42Cpo23J4hkNB4D6Fu2uM5hGenhLw5WDE

Hi Lou. That is an excellent resource! Thanks for sharing this.