Anne, your post reminded me of one of our Blue Jays---he has learned how to call like a Red-Tailed Hawk!
He will use his bi-lingual ability to try to frighten other birds away from the food I put out.
They stopped paying attention to him a long time ago.
I'm the only one who pays any attention to him---he settles for that!

Jays make some calls you would not expect. They are almost as good as mockingbirds when it comes to fooling you. I did not really notice until a couple of years ago when my rowdy crew arrived. One has a call like a bell. The hawk call is ignored by most of the birds, but the squirrels fall for it quit often.