Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2021 |  |
VRS Castricum | 27 February | |
VRS Castricum | 14 April | |||
| 2020 | |
VRS Castricum | 12 April | |
VRS Castricum | 12 April | |||
| 2019 | |
VRS Castricum | 30 March | |
VRS Castricum | 15 April | |||
| 2018 | |
VRS Castricum | 2 March | |
VRS Castricum | 6 May | |||
| 2012 | |
VRS Castricum | 8 May | |
VRS Castricum | 8 May | |||
| 2009 | |
VRS Castricum | 3 May | |
VRS Castricum | 3 May | |||
| 2005 | |
VRS Castricum | 23 April | |
VRS Castricum | 23 April | |||
| 1996 | |
VRS Castricum | 23 May | |
VRS Castricum | 23 May | |||
| 1995 | |
VRS Castricum | 24 April | |
VRS Castricum | 24 April |
