Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 1998 |  |
VRS Castricum | 20 October | |
VRS Castricum | 20 October | |||
| 1988 | |
VRS Castricum | 30 September | |
VRS Castricum | 30 September | |||
| 1978 | |
VRS Castricum | 15 November | |
VRS Castricum | 15 November | |||
| 1976 | |
VRS Castricum | 30 October | |
VRS Castricum | 30 October | |||
| 1975 | |
VRS Castricum | 4 November | |
VRS Castricum | 4 November | |||
| 1971 | |
VRS Castricum | 15 October | |
VRS Castricum | 15 October |
