If you’re wondering why you’re hearing the sound of a ship’s foghorn coming from the middle of the reed beds in the spring, it’s because of the Eurasian bittern (Botaurus stellaris). The Eurasian bittern lives completely hidden among the reeds, and only flies around in the twilight hours. It does not nest every year in Vanhankaupunginlahti.
An Eurasian bittern hiding in the reeds, photo Eero Haapanen.