Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2012 |  |
VRS Castricum | 19 May | |
VRS Castricum | 19 May | |||
| 2010 | |
VRS Castricum | 29 June | |
VRS Castricum | 29 June | |||
| 2001 | |
VRS Castricum | 23 June | |
VRS Castricum | 23 June | |||
| 1998 | |
VRS Castricum | 11 July | |
VRS Castricum | 12 July | |||
| 1997 | |
VRS Castricum | 22 June | |
VRS Castricum | 22 June | |||
| 1996 | |
VRS Castricum | 6 January | |
VRS Castricum | 6 January | |||
| 1995 | |
VRS Castricum | 31 December | |
VRS Castricum | 31 December | |||
| 1986 | |
VRS Castricum | 20 February | |
VRS Castricum | 20 February | |||
| 1985 | |
VRS Castricum | 20 February | |
VRS Castricum | 20 February | |||
| 1979 | |
VRS Castricum | 8 January | |
VRS Castricum | 8 January |
