Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2021 |  |
VRS Castricum | 29 May | |
VRS Castricum | 29 May | |||
| 2019 | |
VRS Castricum | 21 September | |
VRS Castricum | 21 September | |||
| 2016 | |
VRS Castricum | 9 May | |
VRS Castricum | 28 August | |||
| 2015 | |
VRS Castricum | 20 August | |
VRS Castricum | 20 August | |||
| 2013 | |
VRS Castricum | 31 August | |
VRS Castricum | 31 August | |||
| 2012 | |
VRS Castricum | 8 September | |
VRS Castricum | 8 September | |||
| 2008 | |
VRS Castricum | 31 August | |
VRS Castricum | 31 August | |||
| 2006 | |
VRS Castricum | 19 August | |
VRS Castricum | 19 August | |||
| 1998 | |
VRS Castricum | 20 September | |
VRS Castricum | 20 September |
