Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2021 |  |
VRS Castricum | 5 May | |
VRS Castricum | 5 May | |||
| 2019 | |
VRS Castricum | 24 August | |
VRS Castricum | 24 August | |||
| 2018 | |
VRS Castricum | 31 August | |
VRS Castricum | 31 August | |||
| 2017 | |
VRS Castricum | 10 August | |
VRS Castricum | 10 August | |||
| 2016 | |
VRS Castricum | 19 August | |
VRS Castricum | 11 September | |||
| 2014 | |
VRS Castricum | 1 August | |
VRS Castricum | 2 August | |||
| 2011 | |
VRS Castricum | 24 March | |
VRS Castricum | 24 March | |||
| 2007 | |
VRS Castricum | 20 August | |
VRS Castricum | 20 August | |||
| 2003 | |
VRS Castricum | 20 May | |
VRS Castricum | 20 May | |||
| 2002 | |
VRS Castricum | 2 August | |
VRS Castricum | 2 August | |||
| 2000 | |
VRS Castricum | 13 August | |
VRS Castricum | 13 August | |||
| 1996 | |
VRS Castricum | 5 September | |
VRS Castricum | 5 September | |||
| 1992 | |
VRS Castricum | 4 July | |
VRS Castricum | 4 July | |||
| 1991 | |
VRS Castricum | 15 August | |
VRS Castricum | 15 August | |||
| 1989 | |
VRS Castricum | 1 May | |
VRS Castricum | 3 September |
