Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2012 |  |
VRS Castricum | 18 August | |
VRS Castricum | 18 August | |||
| 2009 | |
VRS Castricum | 31 October | |
VRS Castricum | 1 November | |||
| 1993 | |
VRS Castricum | 17 November | |
VRS Castricum | 17 November | |||
| 1991 | |
VRS Castricum | 24 November | |
VRS Castricum | 24 November | |||
| 1984 | |
VRS Castricum | 10 November | |
VRS Castricum | 10 November | |||
| 1974 | |
VRS Castricum | 21 October | |
VRS Castricum | 21 October |
