The Cetti's Warbler is a skulking bird and can prove very difficult to see.
You will hear it always first before seeing it, if you are lucky.
Cetti's Warblers signal their presence with a loud and very characteristic song that you will recognize immediately and never forget.

First 4 photos: Zouweboezem, Lexmond, The Netherlands, 15 April 2019
Last photo: Huizen, The Netherlands, 6 April 2020