Sandwich Tern

Dark-blue ring with a white 3 alpha-numeric code and metal ring.

note 1 : Always letter 'N' on first position; followed by one letter and one numeric (e.g. NV2 or N2V); or one numeric and one numeric (e.g. N12); or one letter and one letter (e.g. NVT)

note 2 : Always letter ‘H’ on first position; followed by one letter and one numeric (e.g. HV2 or H2V); or one numeric and one numeric (e.g. H12); or one letter and one letter (e.g. HVT)

note 3 : Always letter ‘J' on first position, followed by one numeric and one numeric (e.g. J12); or one letter and one numeric and a ‘.' [dot] in the code in a random position (either between first and second digit, or between second and third) (e.g. J.2T or J2.V)

note 4 : a joint project of the Research Institute for Nature and Forest/INBO, Bureau Waardenburg and Ringgroup Delta. This project started in 2010 and each year (except in 2011) both adults and juveniles have been colourringed.

note 5 : we use colour-rings in order to gain information on migration, habitat use, juvenile dispersal, age of return and recruitment to the breeding colonies in the southwest of The Netherlands or beyond.

note 6 : used letters are : A, C, F, H, K, L, N, P, R, S, T, V, X, Z.

note 7 :

Yellow ring (4 mm high, without code) (on left tarsus, exceptionally right) and metal ring (on the right tarsus, exceptionally left).

note 1 : a joint project of the Research Institute for Nature and Forest/INBO, Bureau Waardenburg and Ringgroup Delta on breeding and feeding ecology. This project will run for the next five years.

note 2 : the colour-ring is added to aid identification of birds (formerly) carrying transmitters in the breeding colonies in the southwest of The Netherlands. Reports from further afield are more than welcome !

Blue ring with a white three alpha code (starting letter 'C') (on one leg) and metal ring (on other leg).

note 1 : used letters are A,B,C,D,F,H,J,K,L,N,P,S,T,V,Z.

note 2 : 

Green ring with a white three alpha code (starting letter 'C') (on one leg) and metal ring (on other leg).

note 1 : used letters are A,B,C,D,F,H,J,K,L,N,P,S,T,V,Z.

note 2 : 

Combination of an orange ring with a black 3 alpha code (starting letter 'C') and metal ring.

note 1 : used letters are A,B,C,D,F,H,J,K,L,N,P,S,T,V,Z.

Combination of orange ring over dark-blue ring (on left leg) and metal ring over white ring with code (3 black letters). (1)

Combination of green over red ring (on left leg) and metal ring over white ring with code (3 black letters). (2)

Combination of a white ring with black 3 alpha code (starting letter 'B' or 'C') and white ring over metal ring (on right leg). (3)

note 1 : white ring with black code (3 black letters) is to be read vertical is on the tarsus and used letters are A, B, C, E, H, I, K, L, N, O, P, S, T, V, X, Z. 
note 2 : birds ringed in France, (SE France , dept. Hérault near Montpellier).
note 3 : (2) : 171 birds ringed in 2010 on 2 colonies, 1st letter is A or B.
note 4 : (3) on the 4th. of  July 2011, some 207 birds have been ringed at Marseillan, Southern France (near Montpellier).

White ring with black code.

note 1 : used codes are AA-ZZ used in the Ebro Delta.

Combination of a yellow ring with a black 3 alpha code, starting letter 'E' (reading down on left tarsus) and metal ring (on right tarsus).

note 1 : rings are yellow with black letters using the letters A, B, C, D, F, H, J, K, L, N, P, S, T, V, Z.

note 2 : other colours and numbers may be used from 2011 but the first letter is always E.

note 3 : birds have been ringed in north-east Scotland by Grampian Ringing Group.

note 4 : 160 birds have been ringed with yellow rings (for chicks reared in the colony).

Combination of :
* red ring with a 3 alpha code, starting letter 'E' (reading down on left tarsus)
* metal ring (on right tarsus).

note 1 : rings are red with letters using the letters A, B, C, D, F, H, J, K, L, N, P, S, T, V, Z.
note 2 : other colours and numbers may be used from 2011 but the first letter is always E.
note 3 : birds have been ringed in north-east Scotland by Grampian Ringing Group.
note 4 : 160 adults with red or yellow rings.

Yellow ring with a black 3 alpha-code (on left tarsus) and metal ring (on right tarsus).

note 1 : letter 'P' is on the lower position.

note 2 :