Most but not all birds are that way; the male is much prettier and striking in color; the females duller in color to protect them from predators during nesting time. I have the clear decals on my windows; they seem to work pretty well; I have some stained glass hangers in some; they don't work as well OR I have dumb doves. They constantly bang into the glass; I'm surprised I've not seen any deceased ones in my flower beds. Let us know if you find something that actually works.