Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2013 |  |
VRS Castricum | 24 March | |
VRS Castricum | 24 March | |||
| 2012 | |
VRS Castricum | 1 February | |
VRS Castricum | 1 February | |||
| 2011 | |
VRS Castricum | 7 May | |
VRS Castricum | 7 May | |||
| 2001 | |
VRS Castricum | 15 July | |
VRS Castricum | 15 July | |||
| 2000 | |
VRS Castricum | 13 August | |
VRS Castricum | 13 August | |||
| 1995 | |
VRS Castricum | 11 March | |
VRS Castricum | 11 March | |||
| 1994 | |
VRS Castricum | 12 May | |
VRS Castricum | 12 May | |||
| 1993 | |
VRS Castricum | 11 May | |
VRS Castricum | 11 May | |||
| 1976 | |
VRS Castricum | 1 February | |
VRS Castricum | 1 February |
