Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2022 |  |
VRS Castricum | 16 March | |
VRS Castricum | 1 December | |||
| 2021 | |
VRS Castricum | 24 March | |
VRS Castricum | 9 November | |||
| 2020 | |
VRS Castricum | 14 March | |
VRS Castricum | 2 December | |||
| 2019 | |
VRS Castricum | 20 January | |
VRS Castricum | 14 November | |||
| 2018 | |
VRS Castricum | 4 August | |
VRS Castricum | 15 November | |||
| 2015 | |
VRS Castricum | 23 September | |
VRS Castricum | 7 October | |||
| 2014 | |
VRS Castricum | 28 September | |
VRS Castricum | 12 November | |||
| 2012 | |
VRS Castricum | 7 October | |
VRS Castricum | 14 November | |||
| 2010 | |
VRS Castricum | 10 April | |
VRS Castricum | 26 October | |||
| 2009 | |
VRS Castricum | 20 October | |
VRS Castricum | 9 November | |||
| 2008 | |
VRS Castricum | 31 March | |
VRS Castricum | 17 April | |||
| 2007 | |
VRS Castricum | 18 July | |
VRS Castricum | 21 October | |||
| 2006 | |
VRS Castricum | 16 July | |
VRS Castricum | 3 November | |||
| 2004 | |
VRS Castricum | 26 September | |
VRS Castricum | 14 November | |||
| 2003 | |
VRS Castricum | 14 April | |
VRS Castricum | 17 October | |||
| 2002 | |
VRS Castricum | 1 April | |
VRS Castricum | 3 December |
