Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2021 |  |
VRS Castricum | 22 April | |
VRS Castricum | 27 April | |||
| 2019 | |
VRS Castricum | 30 October | |
VRS Castricum | 30 October | |||
| 2017 | |
VRS Castricum | 22 January | |
VRS Castricum | 17 November | |||
| 2014 | |
VRS Castricum | 26 December | |
VRS Castricum | 26 December | |||
| 2013 | |
VRS Castricum | 21 January | |
VRS Castricum | 22 November | |||
| 2011 | |
VRS Castricum | 23 February | |
VRS Castricum | 22 November | |||
| 2010 | |
VRS Castricum | 4 January | |
VRS Castricum | 30 January | |||
| 2008 | |
VRS Castricum | 11 February | |
VRS Castricum | 11 February | |||
| 2005 | |
VRS Castricum | 3 March | |
VRS Castricum | 3 March | |||
| 2003 | |
VRS Castricum | 8 January | |
VRS Castricum | 14 February | |||
| 2001 | |
VRS Castricum | 20 October | |
VRS Castricum | 20 October | |||
| 2000 | |
VRS Castricum | 12 March | |
VRS Castricum | 23 December | |||
| 1998 | |
VRS Castricum | 8 November | |
VRS Castricum | 8 November | |||
| 1996 | |
VRS Castricum | 6 January | |
VRS Castricum | 12 October | |||
| 1995 | |
VRS Castricum | 8 December | |
VRS Castricum | 29 December | |||
| 1993 | |
VRS Castricum | 2 January | |
VRS Castricum | 2 January | |||
| 1991 | |
VRS Castricum | 29 July | |
VRS Castricum | 29 July | |||
| 1988 | |
VRS Castricum | 4 October | |
VRS Castricum | 1 November | |||
| 1987 | |
VRS Castricum | 30 January | |
VRS Castricum | 7 December | |||
| 1986 | |
VRS Castricum | 16 November | |
VRS Castricum | 16 November | |||
| 1985 | |
VRS Castricum | 22 October | |
VRS Castricum | 22 October | |||
| 1984 | |
VRS Castricum | 7 August | |
VRS Castricum | 27 December | |||
| 1983 | |
VRS Castricum | 3 August | |
VRS Castricum | 21 October | |||
| 1982 | |
VRS Castricum | 2 April | |
VRS Castricum | 5 November | |||
| 1981 | |
VRS Castricum | 7 May | |
VRS Castricum | 11 December | |||
| 1980 | |
VRS Castricum | 16 October | |
VRS Castricum | 30 November | |||
| 1979 | |
VRS Castricum | 5 August | |
VRS Castricum | 6 October | |||
| 1978 | |
VRS Castricum | 23 September | |
VRS Castricum | 29 November | |||
| 1977 | |
VRS Castricum | 20 August | |
VRS Castricum | 7 October | |||
| 1975 | |
VRS Castricum | 5 October | |
VRS Castricum | 5 October | |||
| 1974 | |
VRS Castricum | 30 September | |
VRS Castricum | 6 October | |||
| 1973 | |
VRS Castricum | 8 September | |
VRS Castricum | 8 September | |||
| 1972 | |
VRS Castricum | 8 October | |
VRS Castricum | 8 October | |||
| 1970 | |
VRS Castricum | 28 September | |
VRS Castricum | 17 October | |||
| 1968 | |
VRS Castricum | 2 October | |
VRS Castricum | 2 October | |||
| 1967 | |
VRS Castricum | 26 September | |
VRS Castricum | 30 September | |||
| 1966 | |
VRS Castricum | 18 September | |
VRS Castricum | 1 October | |||
| 1964 | |
VRS Castricum | 25 September | |
VRS Castricum | 1 October | |||
| 1963 | |
VRS Castricum | 14 October | |
VRS Castricum | 14 October | |||
| 1962 | |
VRS Castricum | 23 September | |
VRS Castricum | 2 October | |||
| 1961 | |
VRS Castricum | 30 October | |
VRS Castricum | 30 October |
