Common Tern

Yellow ring with a black three alpha code.

note 1 : always letter 'N' or 'H' on the first position.

note 2 : the letter N or H is followed by two letters (eg. NVN or NNV). 

note 3 : used letters are : A, C, F, H, K, L, N, P, R, S, T, V, X, Z.

note 4 : these codes were used in 2017-2018 on both adult and juvenile birds during the breeding season in the southwest of the Netherlands.

note 5 : a joint project of the Research Institute for Nature and Forest (INBO), Bureau Waardenburg and Ringgroup Delta.

note 6 : we use colour-rings in order to gain information on habitat use, juvenile dispersal, age of return and recruitment to the breeding colonies in the southwest of The Netherlands or beyond.

note 7 :

Yellow ring with a black three alpha-numeric code.

note 1 : always letter 'N' or 'H' on the first position OR always letter 'N' on the 2nd or 3rd position (eg. 2NA or 2AN).

note 2 : the letter N is followed by one letter and one number (eg. NV2 or N2V).  
note 2a : the letter H is followed by one letter and one number (eg. HV2 or H2V), by two letters (eg. HVN or HNV) or by two numbers (eg. H42). 

note 3 : used letters are : A, C, F, H, K, L, N, P, R, S, T, V, X, Z. Used numbers are 1, 2, 3, 4, 5, 6, 7, 8, 9.

note 4 : these codes were used in 2017-2019 on both adult and juvenile birds during the breeding season in the southwest of the Netherlands.

note 4 : IMPORTANT NOTICE: about 75 double codes starting with N (and followed by a letter and a number) were issued in 2017 by another project (ref to other project). These only differ in the position of the CR on the bird: mostly right tarsus for the Polish project, mostly left tarsus for the Dutch project. Please when reading a yellow Common Tern CR with an N on the first position note on what leg the CR is positioned.

note 5 : these codes were used in 2017-2018 on both adult and juvenile birds during the breeding season in the southwest of the Netherlands.

note 6 : a joint project of the Research Institute for Nature and Forest (INBO), Bureau Waardenburg and Ringgroup Delta.

note 7 : we use colour-rings in order to gain information on habitat use, juvenile dispersal, age of return and recruitment to the breeding colonies in the southwest of The Netherlands or beyond.

note 8 :

White ring with a black three alpha code.

note 1 : always letter 'N' or 'H' on the first position.

note 2 : the letter N of H is followed by two letters (eg. NVN or NNV).  

note 3 : used letters are : A, C, F, H, K, L, N, P, R, S, T, V, X, Z.

note 4 : these codes were used in 2016-2018 on both adult and juvenile birds during the breeding season in the southwest of the Netherlands.

note 5 : a joint project of the Research Institute for Nature and Forest (INBO), Bureau Waardenburg and Ringgroup Delta.

note 6 : we use colour-rings in order to gain information on habitat use, juvenile dispersal, age of return and recruitment to the breeding colonies in the southwest of The Netherlands or beyond.

note 7 :

White (or yellow) ring with a black three alpha-numeric code.

note 1 : letter 'N' or 'H' on the first position OR letter 'N' on the 2nd or 3rd position (eg. 2NA or 2AN).

note 2 : the letter N or H is followed by one letter and one number (eg. NV2 or N2V) or by two numbers (eg. N42). 

note 3 : used letters are : A, C, F, H, K, L, N, P, R, S, T, V, X, Z. Used numbers are 1, 2, 3, 4, 5, 6, 7, 8, 9.

note 4 : IMPORTANT NOTICE: about 100 double codes starting with H (and followed by a letter and a number) were issued in 2019 by another project (https://www.cr-birding.org/node/5104). These differ in the presence of a dot after the H. Please when reading a white Common Tern CR with a H on the first position note if a dot is present in the code.

note 5 : a joint project of the Research Institute for Nature and Forest (INBO), Bureau Waardenburg and Ringgroup Delta.

note 6 : we use colour-rings in order to gain information on habitat use, juvenile dispersal, age of return and recruitment to the breeding colonies in the southwest of The Netherlands or beyond.

note 7 :

Blue ring with a white three alpha code.

note 1 : always letter 'N' on the first position.

note 2 : the letter N is followed by two letters (eg. NVN or NNV). 

note 3 : used letters are : A, C, F, H, K, L, N, P, R, S, T, V, X, Z.

note 4 : these codes were used in 2013-2015 on both adult and juvenile birds during the breeding season in the southwest of the Netherlands.

note 5 : a joint project of the Research Institute for Nature and Forest (INBO), Bureau Waardenburg and Ringgroup Delta.

note 6 : we use colour-rings in order to gain information on habitat use, juvenile dispersal, age of return and recruitment to the breeding colonies in the southwest of The Netherlands or beyond.

note 7 :

Blue ring with a white three alpha-numeric code.

note 1 : always letter 'N' on the first position.

note 2 : the letter N is followed by one letter and one number (eg. NV2 or N2V) or by two letters (eg. NVN or NNV).  

note 3 : used letters are : A, C, F, H, K, L, N, P, R, S, T, V, X, Z. Used numbers are 1, 2, 3, 4, 5, 6, 7, 8, 9.

note 4 : these codes were used in 2013-2015 on both adult and juvenile birds during the breeding season in the southwest of the Netherlands.

note 5 : a joint project of the Research Institute for Nature and Forest (INBO), Bureau Waardenburg and Ringgroup Delta.

note 6 : we use colour-rings in order to gain information on habitat use, juvenile dispersal, age of return and recruitment to the breeding colonies in the southwest of The Netherlands or beyond.

note 7 :

Blue ring with a white two numeric code.

note 1 : used numbers are 1, 2, 3, 4, 5, 6, 7, 8, 9.

note 2 : these codes were used in 2010-2013 on both adult and juvenile birds during the breeding season in the southwest of the Netherlands.

note 3 : a joint project of the Research Institute for Nature and Forest (INBO), Bureau Waardenburg and Ringgroup Delta.

note 4 : we use colour-rings in order to gain information on habitat use, juvenile dispersal, age of return and recruitment to the breeding colonies in the southwest of The Netherlands or beyond.

note 5 :

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

note 1 : to be read from bottom till top.

note 2 :

Red ring with a white three numeric code.

note 1 : used codes: 0.00-0.99

note 2 : birds ringed in Staffordshire, UK.

note 3 : 

White flag with a black three alpha-numeric code.

note 1 : used letters as first letter : A, B, C, E, F ,H , J,K, L, M ,U, V, X, Y, Z.

note 2 :