Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2015 |  |
VRS Castricum | 16 August | |
VRS Castricum | 16 August | |||
| 2011 | |
VRS Castricum | 4 June | |
VRS Castricum | 4 June | |||
| 2010 | |
VRS Castricum | 25 January | |
VRS Castricum | 18 October | |||
| 2005 | |
VRS Castricum | 23 July | |
VRS Castricum | 23 July | |||
| 2003 | |
VRS Castricum | 9 November | |
VRS Castricum | 9 November | |||
| 2002 | |
VRS Castricum | 18 June | |
VRS Castricum | 18 June | |||
| 2001 | |
VRS Castricum | 25 November | |
VRS Castricum | 25 November | |||
| 2000 | |
VRS Castricum | 17 November | |
VRS Castricum | 17 November | |||
| 1997 | |
VRS Castricum | 10 January | |
VRS Castricum | 10 January | |||
| 1996 | |
VRS Castricum | 6 February | |
VRS Castricum | 1 December | |||
| 1995 | |
VRS Castricum | 11 November | |
VRS Castricum | 26 November | |||
| 1992 | |
VRS Castricum | 29 July | |
VRS Castricum | 29 July |
