Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2020 |  |
VRS Castricum | 20 May | |
VRS Castricum | 20 May | |||
| 2019 | |
VRS Castricum | 27 May | |
VRS Castricum | 27 May | |||
| 2018 | |
VRS Castricum | 6 March | |
VRS Castricum | 1 May | |||
| 2017 | |
VRS Castricum | 11 August | |
VRS Castricum | 11 August | |||
| 2016 | |
VRS Castricum | 30 August | |
VRS Castricum | 30 August | |||
| 2014 | |
VRS Castricum | 5 May | |
VRS Castricum | 5 May | |||
| 2013 | |
VRS Castricum | 30 March | |
VRS Castricum | 24 April | |||
| 2009 | |
VRS Castricum | 22 May | |
VRS Castricum | 22 May | |||
| 2007 | |
VRS Castricum | 17 June | |
VRS Castricum | 17 June | |||
| 2006 | |
VRS Castricum | 17 April | |
VRS Castricum | 17 April | |||
| 2004 | |
VRS Castricum | 3 August | |
VRS Castricum | 3 August | |||
| 2003 | |
VRS Castricum | 14 June | |
VRS Castricum | 14 June | |||
| 2002 | |
VRS Castricum | 14 June | |
VRS Castricum | 14 June | |||
| 2000 | |
VRS Castricum | 15 July | |
VRS Castricum | 15 July | |||
| 1996 | |
VRS Castricum | 27 April | |
VRS Castricum | 5 May | |||
| 1991 | |
VRS Castricum | 3 May | |
VRS Castricum | 3 May | |||
| 1987 | |
VRS Castricum | 26 February | |
VRS Castricum | 26 February | |||
| 1971 | |
VRS Castricum | 14 January | |
VRS Castricum | 14 January |
