Tuk-Tucking is usually because a cat is on the prowl. Cats sometimes hunker down and wait for the unsuspecting birds to come to them and a watchful Blackbird will alarm for as long as it takes to make it go away.
Today I was privileged to watch a pair of Blackbirds courting. I first noticed them apparently looking for food about a yard apart and while I waited for the seemingly inevitable squabble over territory which never came he suddenly started posing in front of her by squatting and feather fluttering. She looked on appreciatively so he chanced a mating move which she declined. This was followed by them coming beak to beak and looking like they were going to fight but it was all handbag stuff. After this he flew up to a low wall but not to be ignored she followed him. Just at the point I thought some kind of climax was being reached he flew in to my plum tree followed by the female and I lost site of both
Don't say that as we are in and out of there all the time as the freezer,washing machine and other equipment are in there. 
Could be quite nice 
if you don't have to go away 
