Beautiful shot Holger! Nise pose! A little dark IMO. I'd bring the exposure up just a tad in order to feel just a little more 'in contact' with the bird.
Nice to see this bird in its habitat Holger. There a few issues for me with this one. The reeds, especially the OOF one over the bird is unfortunate and the exposure looks like it needs to bumped up by a third or two. Im sure its not easy even getting a shot like this, so maybe this guy will walk into a nice opening for you one day. Nice work.
We can nicely see how this heron got its name. I like the habitat aspect of the image, and the pose is good with a vertical comp that fits it in beautifully. I kinda like the darkish exposure. There is one oof diagonal grayish reed running across the subject that I wish was not there.