Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2021 | Cap Gris-Nez | 21 March | Cap Gris-Nez | 25 October | |||||
| 2018 | Cap Gris-Nez | 11 March | Cap Gris-Nez | 11 March | |||||
| 2017 | Cap Gris-Nez | 22 April | Cap Gris-Nez | 22 April | |||||
| 2014 | Cap Gris-Nez | 3 September | Cap Gris-Nez | 3 September | |||||
| 2013 | Cap Gris-Nez | 9 March | Cap Gris-Nez | 12 November | |||||
| 2012 | Cap Gris-Nez | 4 February | Cap Gris-Nez | 15 April | |||||
| 2011 | Cap Gris-Nez | 2 March | Cap Gris-Nez | 13 November | |||||
| 2009 | Cap Gris-Nez | 18 April | Cap Gris-Nez | 13 September | |||||
| 2008 | Cap Gris-Nez | 5 April | Cap Gris-Nez | 22 November | |||||
| 2007 | Cap Gris-Nez | 4 May | Cap Gris-Nez | 4 May | |||||
| 2006 | Cap Gris-Nez | 7 March | Cap Gris-Nez | 23 August | |||||
| 2005 | Cap Gris-Nez | 21 April | Cap Gris-Nez | 20 October | |||||
| 1987 | Cap Gris-Nez | 19 October | Cap Gris-Nez | 20 October | |||||
| 1986 | Cap Gris-Nez | 21 October | Cap Gris-Nez | 21 October | |||||
| 1977 | Cap Gris-Nez | 19 November | Cap Gris-Nez | 19 November |
