The Quacker Singers ?

Maybe, but I've no idea .Spotted on Hardenbergstraße so went back .I like birds but it's  not every day you see the like of these.
Yellow is a constant colour in Berlin as are cars , pigeons and crows .Hence the main had depth and mystery ( for me ).Extra ) Once over the street here you see them and very large they are. All remains a mystery but better these than many things .

* Mystery solved via Dr Google .Absolutely amazing.
Will get permissions 1st and link tomorrow .Very subtle history and protest.Berlin is never without surprises .Impossible to be bored :)