Collared Doves

I am not that fond of collared doves. When they are sitting quietly their call is a contented coo coo coo, but they shriek as they fly with a sound that grates on my ears like chalk on a blackboard. Having said that, however, I have just noticed that they are conspicuous by their absence this year - I can't recall having heard or seen any, and usually there are dozens of them about.