Lesser Black-backed Gull

Yellow ring with black four alpha-numeric code (ending letter 'B').

note 1 : birds are ringed near Cambridge (Cambs) or Doncaster (North Notts).

note 2 :
 

Yellow ring with a black three alpha code : starting letter 'M' followed by a colon ':' and two letters.

note 1 : used letters : all but F, I, O, Q.

note 2 :

Black ring with a white three alpha-numeric code [number/letter/F]. 

note 1 : birds ringed at Flat Holm Island, Cardiff.

note 2 : about 200 birds ringed in 2003 and 2010.

note 3 : if middle letter  = A, B, C, D, E, H, J, K, L or M then birds ringed in 2003.

note 4 : if middle letter = N, P, S, T, U, V, W, X, Y or Z then birds ringed in 2010.

note 5 : number = 0 - 9.

note 6 : Example codes are:  2AF, 6EF, 9MF, 2XF, 5ZF.

White ring with a black four alpha-numeric code, starting letter 'Y' followed by ' : ' and three numbers.

note 1 : used codes are Y:001 - Y:999.

Red ring with a white four alpha-numeric code, starting letter 'U' (on right leg) and metal ring.

note 1 : starting letter 'U', followed by a number and two letters.

note 2 : 

Orange ring with a black four alpha-numeric code :
starting letter 'A' / : / letter / number / number.

note 1 : used codes are A:A01, A:A02, ... A:Z00, A:Z99.

note 2 :

Yellow ring with a black five alpha-numeric code (HXxxx , HAxxx , HVxxx , HExxx, ...). 

note 1 : xxx can be a numeric or an alpha-numeric code.

note 2 : codes are like HX234, HA456, HV500, HE853 : two letters and 3 numbers or HXE67 : three letters and two numbers.

note 3 : rings are to be read from bottom to top, most rings have a “checkpoint”.

note 4 : birds are ringed at Schleswig- Holstein and Hamburg.

note 5 : some rings are used at Herring Gulls, see this species.

note 6 : same codes are used in other colours, therefore please note colour of ring and inscription.

note 7 : 

Black ring with a white three alpha-numeric code : n.xn or nxn, where n is a number and x a letter. (the '.' = dot -if present- is a check character)

note 1 : birds ringed on Guernsey.

note 2 : the dot can be in a high, mid or low point on the ring. The colour rings are usually on the right tarsus, with a metal ring on the left tarsus.

note 3 : details of all my gull colour ring projects are available on the web site. All birds are ringed in the Bailiwick of Guernsey.

note 4 : Annual Reports are available on the Guernsey Gulls web site (www.guernseygulls.co.uk) and also on the Guernsey Gulls Blogspot (www.guernseygulls.blogspot.com).
Check also : http://www.paulveron.com/2013%20GuernseyGulls%20Annual%20Report.html.

note 5 : 

Light-green / lime ring with a black two alpha code.

note 1 : used codes are with a ":" or a "+" between the two letters.

note 2 :

Pale-blue ring with a black two alpha code.

note 1 : used codes are with a ":" or a "+" between the two letters.

note 2 :