Do squirrels and turtles prey upon pigeons? Should I be concerned?

Beleive it or not. I was with my son last Sunday. There was a turtle crossing the road. I stopped and picked it up. Had it for 2 days.Gave it to my neighbor who has a pond. He is 4 houses down. Today I see something in front of my house on the street. Im like what the hell. Its the turtle. Call...