Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2019 | Hobokense Polder | 30 March | Hobokense Polder | 30 March | |||||
| 2018 | Hobokense Polder | 19 April | Hobokense Polder | 19 April | |||||
| 2016 | Hobokense Polder | 29 October | Hobokense Polder | 29 October | |||||
| 2015 | Hobokense Polder | 25 October | Hobokense Polder | 25 October | |||||
| 2011 | Hobokense Polder | 15 October | Hobokense Polder | 15 October | |||||
| 2008 | Hobokense Polder | 4 October | Hobokense Polder | 11 October | |||||
| 2007 | Hobokense Polder | 2 October | Hobokense Polder | 12 November | |||||
| 2006 | Hobokense Polder | 29 October | Hobokense Polder | 5 November |
