Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2021 | De Horde (Lopik) | 8 October | De Horde (Lopik) | 8 October | |||||
| 2018 | De Horde (Lopik) | 13 October | De Horde (Lopik) | 13 October | |||||
| 2017 | De Horde (Lopik) | 17 April | De Horde (Lopik) | 15 October | |||||
| 2016 | De Horde (Lopik) | 1 May | De Horde (Lopik) | 30 October | |||||
| 2015 | De Horde (Lopik) | 25 October | De Horde (Lopik) | 25 October | |||||
| 2014 | De Horde (Lopik) | 7 September | De Horde (Lopik) | 27 September | |||||
| 2012 | De Horde (Lopik) | 6 October | De Horde (Lopik) | 6 October | |||||
| 2011 | De Horde (Lopik) | 14 October | De Horde (Lopik) | 14 October |
