Waarnemingen bij een vermoedelijk gemengd broedpaar Dougalls stern, Sterna dougallii , X visdief, Sterna hirundo te Knokke

From 9 May to 9 August 1976 a Roseate Tern resided in the colony of Common Terns at the Zwin (Knokke). It was apparently a male that eventually palred with a female Common Tern. At least one chick was raised. To avoid disturbance, I did not approach the nest, take photographs or ring the chick(s). This bird is the first Sterna dougallii observed in Belgium.