[n = 6]
| Year / Period | From | To | Established | Ecol. effects |
|---|---|---|---|---|
| unknown | Unknown | Denmark | established | unknown |
| unknown | Unknown | Germany | established | |
| 1913 | USA | France | established | |
| 1920 | Netherlands | Belgium | established | |
| 1920 | Unknown | Netherlands | established | |
| 1995 | Unknown | Poland | established | some |