Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2021 |  |
VRS Castricum | 6 September | |
VRS Castricum | 6 September | |||
| 2017 | |
VRS Castricum | 9 September | |
VRS Castricum | 9 September | |||
| 2016 | |
VRS Castricum | 23 November | |
VRS Castricum | 23 November | |||
| 2012 | |
VRS Castricum | 28 October | |
VRS Castricum | 28 October | |||
| 2011 | |
VRS Castricum | 4 June | |
VRS Castricum | 4 June | |||
| 2010 | |
VRS Castricum | 22 December | |
VRS Castricum | 22 December | |||
| 2007 | |
VRS Castricum | 10 March | |
VRS Castricum | 10 March | |||
| 2006 | |
VRS Castricum | 3 October | |
VRS Castricum | 3 October | |||
| 2005 | |
VRS Castricum | 12 October | |
VRS Castricum | 12 October | |||
| 1999 | |
VRS Castricum | 3 November | |
VRS Castricum | 3 November | |||
| 1997 | |
VRS Castricum | 1 January | |
VRS Castricum | 13 November | |||
| 1996 | |
VRS Castricum | 26 December | |
VRS Castricum | 26 December | |||
| 1994 | |
VRS Castricum | 9 August | |
VRS Castricum | 9 August | |||
| 1992 | |
VRS Castricum | 25 January | |
VRS Castricum | 25 January | |||
| 1985 | |
VRS Castricum | 18 February | |
VRS Castricum | 18 February | |||
| 1981 | |
VRS Castricum | 21 December | |
VRS Castricum | 21 December | |||
| 1972 | |
VRS Castricum | 17 October | |
VRS Castricum | 17 October | |||
| 1968 | |
VRS Castricum | 16 November | |
VRS Castricum | 16 November | |||
| 1966 | |
VRS Castricum | 29 September | |
VRS Castricum | 29 September |
