It had a good start, and the concept was amazing. Bernhard was such an interesting character, and I wish I learned more about him. The different POVs are well-written, and since the writing style changes it feels like a different person. It's obvious when the POV changes, and I love that. I saw some reviews that disagreed on this, so beware of that.
But the damn birds... There were so much talk about birds, and I don't understand why? If you have a big interest in birds it probably won't affect you, but I saw many other reviews that agreed there were too much stuff about birds. It would've been fine if I came prepared for that, but there is no mention of birds being such a big part of the book, and the birds give no meaning or sense to the story.