Marks on immature Yellow-legged Gull (2 Viewers)

[SueO]

On another thread we were posting photos of birds we'd seen and I posted a bird I got on Isla Graciosa, Canary Islands. That triggered something I've wondered about. I saw a young Yellow-legged Gull on the island that had horizontal marks on the lower leg. I haven't been able to find any information about that. It's been years! I'm still curious. Here is a photo of the bird. I don't recall seeing these marks on other gulls. Have I just been non-observant? Sorry-messed up the title--meant to say marks on legs. EDIT: Unfortunately, I don't have access to the original photo right now. This came off an old blog post and it's a bit small. On my computer I can hit a +that shows up after clicking on the photo and make it a little bigger--don't know if everybody has that option. EDIT AGAIN. Found I could enlarge it a bit so posted a new, larger version.

 

[Alexander Stöhr]

Hello Sue,

these markings are often named (dark) shins in the literature and are a feature of 1st cycle Lesser black Gulls, but not diagnostic. See here, thanks Lou again!

Yellow-legged or Lesser black-backed Gull?- Hastings, UK

Taken today 01/08/23. It's about time I properly got to grips with these gulls and I need your help. My thoughts are that contrasty head and clear mask and a pretty heavy bill whiteish belly and undertail point to YLG, but I'm really not confident enought yet to call it myself. If this is YLG...

www.birdforum.net

Edit: here are some Gulls with darkish shins

https://flic.kr/p/S9CHpZ

(juvenile LBBG, Nieblum, Föhr, N-Germany, august 2009)

https://flic.kr/p/RV3gj5

https://flic.kr/p/S63RxQ

(juvenile YLG, Heidelberg, SW-Germany)

https://flic.kr/p/QUDMbV

(2nd cy LBBG, Burgstaaken, Fehmarn, N-Germany)

Here is a juvenile Caspian Gull, that seems to have dark shins, but difficult to be sure its not an artefact (digital zoom, haze and small sensor you know, oh yes and 'high' ISO for such a small sensor) (all Steppenmöwe K1 19.7.16 Prenzlau, NE-Germany, 19.07.2016)

https://flic.kr/p/2aZNh9L

 

[SueO]

Thank-you, Alexander (and Lou). We anchored off Isla Graciosa in 2008. Long time to have this bit of minutia floating around in the grey matter folds! That was the first, and last time I ever noticed that marking on any gull.

 

[HH75]

Very interesting to see these marks on Yellow-legged Gulls and Caspian Gull. Here in Ireland, I most associate them with Lesser Black-backed Gull, with Yellow-legged Gulls often standing out due to lacking them, among other features. I imagine they must be rarer in that species. Obviously, I know that Atlantic island Yellow-legged Gulls have a tendency to show these more often.