Lesser Black-backed Gull

Red ring with a white four alpha-numeric code, starting OR ending letter "G" (Gipuzkoa).

note 1 :

White ring with a black four alpha code, starting letter 'N' followed by a colon ":"

note 1 :

Black ring with a white four alpha code, starting letter "G", “G”, followed colon ":"

note 1 : the project runs in Gipuzkoa, Spain but also in Bizkaia.

note 2 :

Red ring with a white four alpha-numeric code, first OR last letter 'G' (=Gipuzkoa)

note 1 : used codes are :
* first letter 'G' : G000 - G999
* last letter 'G' : 000.G - 999.G ; A11:G - Y99:G ; Y00:G ... 11A:G - 00Y:G
* 1A1:G - 0Y0:G
* not used letters : B, E, I, O, Q, S, Z.
* the project runs in Gipuzkoa, Spain but also in Bizkaia and Navarra.

note 2 :

Pale-Blue ring with a 2 alpha-numeric code code

note 1 : rings are placed above the knee (on the tibia) for better observation results in the colony (high vegetation) and on rubbish-dumps. All other colours (with vertical placed codes) above the knee are also part of this project.

note 2 : In some series  used dots (1.A), colons (1:A) or single or double bars (1|A or 1||A). Those additional marks are part of the code

note 3 : In some series is an additional plain marker present at the other tibia, this marker is part of the combination.

note 4: Same codes can be used by other large gull species. If you have doubts about the species and/or code, please note the age and position of all the rings, including the metal ring.

note 5: used letters/numers are : A, B, C, D, E, F, G, H, J, K, L, M, N, P, R, S, T, U, V, W, X, Y, Z, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + and =. Only the letters I, O and Q are never used

note 6: In this project are also used a combination of two coloured rings with both one letter or number at each tibia.

Yellow ring with a black four alpha-numeric code , starting letter "B" followed by a colon ":" and three numbers.

note 1 : example : B:084.

note 2 :

Dark-green ring with a white four alpha-numeric code (on left tarsus) and metal ring (on right tarsus).

note 1 : starting code is letter "B:" (note the colon) followed by three numbers.

note 2 :

Black ring with a white four alpha code, starting letters 'KU' or 'KX'.

note 1 : 

Yellow ring with a black code 5 alpha code (starting letter 'H') and metal ring (on other leg).

note 1 :

Yellow ring with a black four alpha-numeric code :
letter / number / number / ":" (colon) / letter "W".

note 1 : used codes are :