its just another variant of the feral pigeon. which originally came from the rock dove. But they have interbred with fancy pigeons etc.
this is a pretty variant none the less.

Thanks Seaburngirl for the info, we have two of those white tailed Pigeons, I think there are pretty too. :o)) x

They are both very pretty and though 'en masse' in city squares they can be a pest, the odd few in the garden give a variety to the garden birds. We have loads and loads of Wood pigeons as we are in the countryside and also the Collared Doves which used to be scarce but since their arrival in the 1950's have spread everywhere.
Most birds if looked at closely have some wonderful markings, so should all be appreciated. So enjoy your two new visitors.