This species used to be considered a rare vagrant in western Europe. However, in 2007 over 1000 white-winged black terns passed the Netherlands on their spring migration to their nesting grounds, in Poland and still further to the east. And four couples stayed to nest in the Netherlands.
What will happen this year? It is still too early to say.
Good news for terns and gulls in Southern Poland. Several new islands are inviting them to breed: here.