This worked for about 2 days and then the birds were smart enough to know it’s not real. So your results may vary. These are cute but the effectiveness is questionable. I didn’t buy here but have a very similar owl I bought locally …seems identical except the coloring on mine is different.
Pizza owl!!!
I still have my pizza owl, next to a non-pizza owl. No birds have flown into my windows since I got them. Maybe the birds around me are just easily fooled 
Heh. I could be the owls are helping them see reflections - that is, see the glass.
These work great 4 us…both with starlings (not good 4 purple martins), deer, hawks, blue jays…etc…we have ours on a long skinny bamboo sticks…so a) it rattles and b) it rotates/turns n the wind. We have 4 of them…by all our eggie gardens and purple martin poles.