Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2017 |  |
VRS Castricum | 23 April | |
VRS Castricum | 2 August | |||
| 2016 | |
VRS Castricum | 20 May | |
VRS Castricum | 20 May | |||
| 2014 | |
VRS Castricum | 12 May | |
VRS Castricum | 19 June | |||
| 2013 | |
VRS Castricum | 19 May | |
VRS Castricum | 19 May | |||
| 2012 | |
VRS Castricum | 13 April | |
VRS Castricum | 15 July | |||
| 2011 | |
VRS Castricum | 7 July | |
VRS Castricum | 16 July | |||
| 2010 | |
VRS Castricum | 20 April | |
VRS Castricum | 21 December | |||
| 2009 | |
VRS Castricum | 2 April | |
VRS Castricum | 2 April | |||
| 2008 | |
VRS Castricum | 6 April | |
VRS Castricum | 6 April | |||
| 2007 | |
VRS Castricum | 17 June | |
VRS Castricum | 4 August | |||
| 2006 | |
VRS Castricum | 27 December | |
VRS Castricum | 27 December | |||
| 2005 | |
VRS Castricum | 4 June | |
VRS Castricum | 4 June | |||
| 2004 | |
VRS Castricum | 23 February | |
VRS Castricum | 4 July | |||
| 2003 | |
VRS Castricum | 17 January | |
VRS Castricum | 17 January | |||
| 2001 | |
VRS Castricum | 13 June | |
VRS Castricum | 7 July | |||
| 2000 | |
VRS Castricum | 9 January | |
VRS Castricum | 4 July | |||
| 1999 | |
VRS Castricum | 4 July | |
VRS Castricum | 4 July | |||
| 1998 | |
VRS Castricum | 2 July | |
VRS Castricum | 2 July | |||
| 1997 | |
VRS Castricum | 23 January | |
VRS Castricum | 23 January | |||
| 1996 | |
VRS Castricum | 23 May | |
VRS Castricum | 9 July | |||
| 1995 | |
VRS Castricum | 5 June | |
VRS Castricum | 5 June | |||
| 1994 | |
VRS Castricum | 17 July | |
VRS Castricum | 17 July | |||
| 1992 | |
VRS Castricum | 25 January | |
VRS Castricum | 25 January | |||
| 1991 | |
VRS Castricum | 9 February | |
VRS Castricum | 9 February | |||
| 1969 | |
VRS Castricum | 12 October | |
VRS Castricum | 12 October | |||
| 1965 | |
VRS Castricum | 10 October | |
VRS Castricum | 10 October |
