Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2020 |  |
VRS Castricum | 20 May | |
VRS Castricum | 20 May | |||
| 2018 | |
VRS Castricum | 20 May | |
VRS Castricum | 29 June | |||
| 2017 | |
VRS Castricum | 27 May | |
VRS Castricum | 2 June | |||
| 2015 | |
VRS Castricum | 7 July | |
VRS Castricum | 7 July | |||
| 2012 | |
VRS Castricum | 24 May | |
VRS Castricum | 25 July | |||
| 2011 | |
VRS Castricum | 5 May | |
VRS Castricum | 9 May | |||
| 2010 | |
VRS Castricum | 9 October | |
VRS Castricum | 9 October | |||
| 2009 | |
VRS Castricum | 11 July | |
VRS Castricum | 11 July | |||
| 2004 | |
VRS Castricum | 30 May | |
VRS Castricum | 30 May | |||
| 2001 | |
VRS Castricum | 6 October | |
VRS Castricum | 6 October | |||
| 1994 | |
VRS Castricum | 12 October | |
VRS Castricum | 12 October |
