Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2011 | Cap Gris-Nez | 1 October | Cap Gris-Nez | 1 October | |||||
| 2009 | Cap Gris-Nez | 28 April | Cap Gris-Nez | 28 April | |||||
| 2008 | Cap Gris-Nez | 24 August | Cap Gris-Nez | 24 August | |||||
| 2007 | Cap Gris-Nez | 4 May | Cap Gris-Nez | 4 May | |||||
| 2005 | Cap Gris-Nez | 23 August | Cap Gris-Nez | 23 August |
