Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2011 |  |
VRS Castricum | 21 May | |
VRS Castricum | 21 May | |||
| 2006 | |
VRS Castricum | 9 June | |
VRS Castricum | 9 June | |||
| 2003 | |
VRS Castricum | 8 May | |
VRS Castricum | 8 May | |||
| 2001 | |
VRS Castricum | 23 August | |
VRS Castricum | 23 August | |||
| 1999 | |
VRS Castricum | 6 September | |
VRS Castricum | 6 September |
