Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2021 | Hobokense Polder | 1 May | Hobokense Polder | 8 October | |||||
| 2020 | Hobokense Polder | 23 October | Hobokense Polder | 27 October | |||||
| 2018 | Hobokense Polder | 20 October | Hobokense Polder | 20 October | |||||
| 2016 | Hobokense Polder | 14 April | Hobokense Polder | 21 April | |||||
| 2015 | Hobokense Polder | 30 April | Hobokense Polder | 27 October | |||||
| 2014 | Hobokense Polder | 15 March | Hobokense Polder | 15 March | |||||
| 2013 | Hobokense Polder | 27 September | Hobokense Polder | 28 September | |||||
| 2012 | Hobokense Polder | 8 April | Hobokense Polder | 30 September | |||||
| 2011 | Hobokense Polder | 17 April | Hobokense Polder | 29 October | |||||
| 2010 | Hobokense Polder | 28 April | Hobokense Polder | 28 April | |||||
| 2007 | Hobokense Polder | 7 October | Hobokense Polder | 27 October |
