Great Black-backed Gull

Green ring with a white four alpha-numeric code.

note 1 :

Green ring with a white four alpha-numeric code, first letter 'X'.

note 1 :

Red ring with a white three alpha code (on left tarsus) and metal ring (on right tarsus).

note 1 : the following letters have not been used : E, G, I, M, O, Q.

note 2 : most rings are fitted so that the code reads from bottom upwards.

Dark-blue ring with a white four alpha-numeric code : letter J and 3 numbers/letters.

note 1: birds are ringed in Norway.

note 2: used letters for the dark-blue rings are: A, C, G, E, H, J, K, L, M, N, P, R, S, T, U, V, X, Y, Z.

Dark-blue with a white three alpha code (starting letter 'A') (on right leg).

note 1 : some 3-4 birds are ringed in the framework of a wildlife rehabilitation centre near Hastings, East Sussex.

note 2 : during 2000 yellow was used, other colours in other years.

Blue ring with a white three alpha-numeric code (number, followed by 2 letters) (on left leg) and metal ring (on right leg)

note 1 :  starting serie 2AA.

note 2 : first birds of study were ringed as pulli on east coast of Ireland during Summer 2009.

note 3 : 

Blue ring with an orange three alpha code.

note 1 :

Yellow ring (on right leg) with a black four alpha-numeric code : starting letter A, followed by a number, followed by 2 more letters. (eg A1AA).

note 1 : the metal BTO is fitted on the left leg.

Yellow 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 (on one leg) and Helgoland or Copenhagen) metal ring (on other leg).

note 1 : used combinations are H00T -  H99T at Amrum (SH)  between 2007 and 2011 , some rings are used at southern DK
note 2 : 2011 – 2014 we will use HL00 – HL99 yellow with black inscription.
note 3 : rings are to be read from bottom to top.
note 4 : other combinations beginning with “H” and using red or yellow rings are used at LBBGs and Herring-Gulls, see there.