By Jo Garbutt - Flickr: Bittern, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=33043685
Rietreier
Sources:
(*) https://en.wikipedia.org/wiki/Eurasian_bittern
(*) https://ebird.org/species/grebit1
(*) https://search.macaulaylibrary.org/catalog?taxonCode=grebit1