Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2013 |  |
VRS Castricum | 28 August | |
VRS Castricum | 28 August | |||
| 2005 | |
VRS Castricum | 12 May | |
VRS Castricum | 13 May | |||
| 2001 | |
VRS Castricum | 25 September | |
VRS Castricum | 25 September | |||
| 1982 | |
VRS Castricum | 6 November | |
VRS Castricum | 6 November |
