Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2023 | Cap Gris-Nez | 3 May | Cap Gris-Nez | 20 May | |||||
| 2022 | Cap Gris-Nez | 24 July | Cap Gris-Nez | 26 September | |||||
| 2021 | Cap Gris-Nez | 18 August | Cap Gris-Nez | 26 September | |||||
| 2020 | Cap Gris-Nez | 9 September | Cap Gris-Nez | 12 October | |||||
| 2019 | Cap Gris-Nez | 12 May | Cap Gris-Nez | 13 May | |||||
| 2017 | Cap Gris-Nez | 4 May | Cap Gris-Nez | 5 May | |||||
| 2015 | Cap Gris-Nez | 14 August | Cap Gris-Nez | 14 August | |||||
| 2014 | Cap Gris-Nez | 15 August | Cap Gris-Nez | 18 August | |||||
| 2012 | Cap Gris-Nez | 2 May | Cap Gris-Nez | 10 September | |||||
| 2011 | Cap Gris-Nez | 11 September | Cap Gris-Nez | 8 October | |||||
| 2010 | Cap Gris-Nez | 2 May | Cap Gris-Nez | 15 September | |||||
| 2009 | Cap Gris-Nez | 18 April | Cap Gris-Nez | 18 April | |||||
| 2008 | Cap Gris-Nez | 6 May | Cap Gris-Nez | 7 September | |||||
| 2007 | Cap Gris-Nez | 4 May | Cap Gris-Nez | 22 September | |||||
| 2006 | Cap Gris-Nez | 7 May | Cap Gris-Nez | 5 September | |||||
| 2005 | Cap Gris-Nez | 16 May | Cap Gris-Nez | 13 September | |||||
| 1961 | Cap Gris-Nez | 23 August | Cap Gris-Nez | 23 August |
