One of my aunts had a bird bath in her back yard. It drew many birds - including crows, who cleaned themselves after devouring their prey.
I got sick of having to clean the blood out of the bird bath, she told me, so I hung old CDs on tree branches nearby. My kids laughed at me, but it worked! The crows disappeared... but the mice population in the neighborhood increased. My neighbors started complaining that families of mice were now living in their garages.
Ever since I put these bird decals on the windows - aimed at keeping small birds from flying into the glass and injuring or killing themselves - our crow population has almost disappeared...
I liked having crows around!
Maybe it's time to remove the decals and see what happens... Have I inadvertently upset nature's balance?!