The silhouette of a raptorial bird alerts the birds of prey, so they will try to avoid the path of the raptorial bird from a long distance. If you put a sticker like this on a glass surface, you can keep away birds from the windows. Many stickers aren't so effective, because they resemble crows, and those are less alarming, because they don't look like a raptorial bird due to their longer beaks and splayed tails.
Size: 36 x 24 cm. Black.
The sticker has to be placed on the outside of the glass surface.
You can often find dead or stunned birds below large glass surfaces or windows. These animals get injured or killed, because they get severe concussion, cervical or skull fractures while they strike windows at a high speed.