Gulls

species: 
Black-headed Gull
scientific name: 
Chroicocephalus ridibundus
notes: 

Dark-green ring with a white four alpha-numeric code (starting letter "N" followed by 3 digits alpha-numeric).

note 1 : used letters are  : A, B, C, F, H, J, K, L, M, N, P, R, S, T, U, V, W and X.

note 2 : used numbers are 0-9.

note 3 : birds ringed since 2022.

note 4 :

email sighting submit: 
colour-ring type: 
Legring : one, coded.
colour-ring colour (of the c-ring): 
Dark Green [G]
colour-ring code (of the c-ring): 
Four alpha-numeric code (4 letters/numbers).
countries where ringed: 
Spain.
First letter/number (of the c-ring): 
N