Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2021 | Cap Gris-Nez | 1 December | Cap Gris-Nez | 31 December | |||||
| 2020 | Cap Gris-Nez | 20 December | Cap Gris-Nez | 20 December | |||||
| 2019 | Cap Gris-Nez | 22 April | Cap Gris-Nez | 24 November | |||||
| 2018 | Cap Gris-Nez | 12 March | Cap Gris-Nez | 22 April | |||||
| 2017 | Cap Gris-Nez | 17 March | Cap Gris-Nez | 16 April | |||||
| 2016 | Cap Gris-Nez | 12 March | Cap Gris-Nez | 12 March | |||||
| 2015 | Cap Gris-Nez | 7 March | Cap Gris-Nez | 7 March | |||||
| 2013 | Cap Gris-Nez | 19 November | Cap Gris-Nez | 19 November | |||||
| 2011 | Cap Gris-Nez | 6 February | Cap Gris-Nez | 6 February | |||||
| 2010 | Cap Gris-Nez | 7 November | Cap Gris-Nez | 7 November | |||||
| 2008 | Cap Gris-Nez | 17 February | Cap Gris-Nez | 17 February | |||||
| 2007 | Cap Gris-Nez | 10 March | Cap Gris-Nez | 29 December | |||||
| 2006 | Cap Gris-Nez | 12 February | Cap Gris-Nez | 12 December | |||||
| 2005 | Cap Gris-Nez | 12 March | Cap Gris-Nez | 18 November | |||||
| 1987 | Cap Gris-Nez | 17 October | Cap Gris-Nez | 18 October |
