Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 2018 | Hobokense Polder | 20 October | Hobokense Polder | 20 October | |||||
| 2017 | Hobokense Polder | 1 October | Hobokense Polder | 1 October | |||||
| 2016 | Hobokense Polder | 22 April | Hobokense Polder | 22 April | |||||
| 2015 | Hobokense Polder | 23 April | Hobokense Polder | 23 April | |||||
| 2014 | Hobokense Polder | 16 March | Hobokense Polder | 23 October | |||||
| 2013 | Hobokense Polder | 3 May | Hobokense Polder | 29 September | |||||
| 2012 | Hobokense Polder | 23 April | Hobokense Polder | 23 April | |||||
| 2010 | Hobokense Polder | 18 April | Hobokense Polder | 18 April | |||||
| 2009 | Hobokense Polder | 5 October | Hobokense Polder | 5 October | |||||
| 2006 | Hobokense Polder | 5 November | Hobokense Polder | 5 November |
