Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2021 |  |
VRS Castricum | 4 February | |
VRS Castricum | 4 February | |||
| 2004 | |
VRS Castricum | 24 August | |
VRS Castricum | 24 August | |||
| 1975 | |
VRS Castricum | 31 August | |
VRS Castricum | 31 August |
