The collapse in populations seems to have been particularly severe in Great Britain, where there was a 95% decline between 1970 and 1998, and Ireland, which had only 1,000–1,500 pairs in the late 1990s.
Minskningen tycks ha varit särskilt drastisk i Storbritannien, där den uppgick till 95% mellan 1970 och 1998, och Irland, som bara har 1000–1500 par kvar.