Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2017 |  |
VRS Castricum | 17 September | |
VRS Castricum | 17 September | |||
| 2010 | |
VRS Castricum | 25 September | |
VRS Castricum | 25 September | |||
| 2009 | |
VRS Castricum | 30 September | |
VRS Castricum | 30 September | |||
| 2005 | |
VRS Castricum | 20 September | |
VRS Castricum | 20 September | |||
| 2003 | |
VRS Castricum | 12 September | |
VRS Castricum | 12 September | |||
| 2002 | |
VRS Castricum | 21 September | |
VRS Castricum | 27 September | |||
| 1991 | |
VRS Castricum | 5 October | |
VRS Castricum | 5 October |
