Phenology
| Year | Migration site | First | Migration site | Last | |||||
|---|---|---|---|---|---|---|---|---|---|
| 1988 | Parnassia, Kennemerduinen | 30 April | Parnassia, Kennemerduinen | 30 April | |||||
| 1985 | Parnassia, Kennemerduinen | 6 September | Parnassia, Kennemerduinen | 11 November | |||||
| 1984 | Parnassia, Kennemerduinen | 10 September | Parnassia, Kennemerduinen | 20 October | |||||
| 1982 | Parnassia, Kennemerduinen | 1 September | Parnassia, Kennemerduinen | 8 September |
