The mysterious bird

It has been days that in the morning I keep hearing a specific bird sound. I am a passionate birds lover, I always try to spot them, recognise them and get familiar with their call. 

The bird I kept hearing gave me a profound sense of peace, and even if I identified it as belonging to the dove family, the Columbidae, its call is different from the more familiar pigeons or doves sound.

I am still trying to figure it out. It is still a mystery!