Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 1999 |  |
VRS Castricum | 22 September | |
VRS Castricum | 30 October | |||
| 1998 | |
VRS Castricum | 7 November | |
VRS Castricum | 12 November | |||
| 1997 | |
VRS Castricum | 21 October | |
VRS Castricum | 29 October | |||
| 1996 | |
VRS Castricum | 10 October | |
VRS Castricum | 8 December | |||
| 1995 | |
VRS Castricum | 1 November | |
VRS Castricum | 22 November | |||
| 1992 | |
VRS Castricum | 18 September | |
VRS Castricum | 27 October | |||
| 1991 | |
VRS Castricum | 7 December | |
VRS Castricum | 8 December | |||
| 1990 | |
VRS Castricum | 13 October | |
VRS Castricum | 24 October | |||
| 1989 | |
VRS Castricum | 1 April | |
VRS Castricum | 19 October | |||
| 1987 | |
VRS Castricum | 4 November | |
VRS Castricum | 4 November |
