Could this be an atlantis?

totoguti · Post by **totoguti** » Fri Nov 09, 2012 6:45 pm

Hi all:
On 14.10.2012 my friend Daniel Velasco saw this gull. A really nice candidate for atlantis . And truly similar to magnus bird.
You can see a couple of pics at my blog:

http://gaviotasyanillas.blogspot.com.es ... antis.html

Rui_Caratão · Post by **Rui_Caratão** » Sun Nov 18, 2012 11:47 am

Thanks, Peter... I will read your article on BB as soon as I could get it, still the recent colonization event of graellsii in Iberia plus hybridization with "lusitanius" type YLG, could probable be a pitfall on "atlantis" identification. I have no more data than the last YLG survey at Berlengas Islands (Peniche), but in 1996 at least 17 mixed pairs were detected, and the same as been going in the North of Spain, probably Antonio could add more.

regards,
Rui

Rui_Caratão · Post by **Rui_Caratão** » Mon Nov 26, 2012 12:42 am

Another atlantis type spotted this last week by Thijs valkenburg at Sagres harbour, Portugal

: IMG_8135 (2) (800x522).jpg (179.09KiB)Viewed 6439 times

: IMG_8132 (2) (800x534).jpg (181.13KiB)Viewed 6439 times

: IMG_8118 (2) (800x533).jpg (150.32KiB)Viewed 6439 times

: IMG_8111 (2) (800x539).jpg (236.52KiB)Viewed 6439 times

: IMG_8097 (2) (800x533).jpg (233.68KiB)Viewed 6439 times

adriaens · Post by **adriaens** » Mon Nov 26, 2012 10:27 am

Hi Rui,

if it is any help: there are 10+ mixed pairs of Yellow-legged x Lesser Black-backed Gull in the Netherlands and Belgium each year, but such atlantis types as you have posted are not recorded here.

marsmuusse · Post by **marsmuusse** » Mon Nov 26, 2012 12:01 pm

The way this dark spotting on the head is distributed, is different from what is found in graellsii or argentatus / argenteus. In graellsii extensive spotting can be found 'in its exteme' in 3cy autumn birds, like 3cy October birds depicted below (red SDJ from Mike, UK):

Argenteus / argentatus in 3cy October can be blochy on the head and neck as well (yellow V3T3 ringed by Kjeld in Denmark):

Still, it is not to be expected to find the pattern as concentrated as in your bird. Often, graellsii and argeteus with spotted heads remain rather clean "open faced" birds,

Rui_Caratão · Post by **Rui_Caratão** » Mon Nov 26, 2012 3:22 pm

Thank you both! I agree that such a strong and restricted head streaking is not to be expected in graellsii , mainly in the malar and from the lores to the upper mandibule area, but see this ind. from january in Portugal
http://www.flickr.com/photos/rstavares/4291915428/

best regards,
Rui

marsmuusse · Post by **marsmuusse** » Mon Nov 26, 2012 7:52 pm

Nice find Rui. Funny subject: gulls. Always an exceptional bird to destroy the general picture!

Lets be more specific on the borders of the atlantis bird's streaking: dense steaking but bordered by the white chin? Now lets find a LBBG with such a pattern?