Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2021 | Cap Gris-Nez | 17 April | Cap Gris-Nez | 27 April | |||||
| 2019 | Cap Gris-Nez | 20 May | Cap Gris-Nez | 20 May | |||||
| 2017 | Cap Gris-Nez | 21 April | Cap Gris-Nez | 21 April | |||||
| 2015 | Cap Gris-Nez | 21 April | Cap Gris-Nez | 21 April | |||||
| 2014 | Cap Gris-Nez | 17 May | Cap Gris-Nez | 17 May | |||||
| 2013 | Cap Gris-Nez | 5 May | Cap Gris-Nez | 5 May | |||||
| 2012 | Cap Gris-Nez | 22 April | Cap Gris-Nez | 22 April | |||||
| 2011 | Cap Gris-Nez | 27 April | Cap Gris-Nez | 27 April | |||||
| 2007 | Cap Gris-Nez | 11 November | Cap Gris-Nez | 11 November |
