Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2017 |  |
VRS Castricum | 24 March | |
VRS Castricum | 24 March | |||
| 2014 | |
VRS Castricum | 1 April | |
VRS Castricum | 1 April | |||
| 2013 | |
VRS Castricum | 14 April | |
VRS Castricum | 14 April | |||
| 2012 | |
VRS Castricum | 11 March | |
VRS Castricum | 23 March | |||
| 2011 | |
VRS Castricum | 18 March | |
VRS Castricum | 27 March | |||
| 2010 | |
VRS Castricum | 24 March | |
VRS Castricum | 24 March | |||
| 2006 | |
VRS Castricum | 14 April | |
VRS Castricum | 14 April | |||
| 2005 | |
VRS Castricum | 1 April | |
VRS Castricum | 1 April | |||
| 2004 | |
VRS Castricum | 26 March | |
VRS Castricum | 26 March | |||
| 2002 | |
VRS Castricum | 25 March | |
VRS Castricum | 5 April | |||
| 2001 | |
VRS Castricum | 30 March | |
VRS Castricum | 31 March | |||
| 1999 | |
VRS Castricum | 28 March | |
VRS Castricum | 28 March | |||
| 1997 | |
VRS Castricum | 13 March | |
VRS Castricum | 17 March | |||
| 1996 | |
VRS Castricum | 21 April | |
VRS Castricum | 21 April | |||
| 1995 | |
VRS Castricum | 13 March | |
VRS Castricum | 1 April | |||
| 1994 | |
VRS Castricum | 26 February | |
VRS Castricum | 26 February | |||
| 1993 | |
VRS Castricum | 13 March | |
VRS Castricum | 13 March | |||
| 1992 | |
VRS Castricum | 5 March | |
VRS Castricum | 8 April | |||
| 1991 | |
VRS Castricum | 7 March | |
VRS Castricum | 26 April | |||
| 1990 | |
VRS Castricum | 27 March | |
VRS Castricum | 7 April | |||
| 1989 | |
VRS Castricum | 16 March | |
VRS Castricum | 16 April | |||
| 1988 | |
VRS Castricum | 11 October | |
VRS Castricum | 11 October | |||
| 1986 | |
VRS Castricum | 5 April | |
VRS Castricum | 12 November | |||
| 1982 | |
VRS Castricum | 5 April | |
VRS Castricum | 1 September | |||
| 1981 | |
VRS Castricum | 27 April | |
VRS Castricum | 27 April | |||
| 1976 | |
VRS Castricum | 24 September | |
VRS Castricum | 24 September |
