About the size of a raven. They have a black back and top of the head; elsewhere, they are grey, yellow, and brown. In Estonia, they can be seen only occasionally and are small in numbers. They live on many waterbodies with thick reed beds. Reed beds in lakes and bays are what offer enough protection for the great bitterns and a safe spot for making a nest. Their behaviour is particular in the event of danger: they stretch out their head and stay motionless, thereby imitating a bundle of dried reed. People used to believe that if this bird decided to live somewhere, misfortune was sure to hit that place soon. According to folklore, it was the bone of a dead person that screamed like that and made a ‘moo’ sound like a cow. This is due to the characteristic loud low cracking song of the great bittern, which reminds of the voice that can be made when blowing into a bottle, which can be heard from kilometres away. Great bitterns are under protection (protection category II).