Gulls

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

Yellow ring with black two numeric code (on left tarsus).

note 1 : used codes are number/number (00-99).

note 2: a "." sign is to be read within the codes.

note 3 : old yellow rings are turning white.

note 3: some 850 birds are ringed from 1996 until 1999. Most of these rings are fallen off.

note 4: Since 2024 codes with a bar are used, used codes are A|A-Z|Z, 0|A-9|Z, A|0-Z|9 and 0|0-9|9

note 5 : 

email sighting submit: 
colour-ring type: 
Legring : one, coded.
colour-ring colour (of the c-ring): 
Yellow [Y]
colour-ring code (of the c-ring): 
Two numeric code (2 numbers).
colour-ring position (of the c-ring): 
Tarsus left.
countries where ringed: 
The Netherlands.