Another new bird

Well it looks like some sort of Pigeon, but I don't see it in my bird book.
 There were three Feral Pigeons plus this white bird, but the cat from next door appeared and they all flew off.  I haven't seen the white one since.  perhaps it will return tomorrow.  
I'm seeing a lot of Pigeons and Magpies  just now, but I think this will stop next week when the children return to the primary school not far from the house.