Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2017 |  |
VRS Castricum | 23 August | |
VRS Castricum | 23 August | |||
| 2012 | |
VRS Castricum | 5 July | |
VRS Castricum | 5 July | |||
| 2003 | |
VRS Castricum | 21 August | |
VRS Castricum | 21 August | |||
| 1996 | |
VRS Castricum | 28 January | |
VRS Castricum | 14 March | |||
| 1991 | |
VRS Castricum | 3 February | |
VRS Castricum | 3 February |
