Absolutely sinnfrei and not even decorative

I bought this as a raven Taubenschreck, and now being tested 1 week. On the first day after we were able to put together this figure among some adjustment, we brought the raven directly on the balcony. This we did with a double-sided tape, because no mounting hardware are included. After everything was installed, I hoped for the promised success, unfortunately without success. The pigeons were irritated the first 2 hours, and then more or less amused and sit on the Ravens.

Would recommend only to save the few euros or attach the good old spikes.