Not a very common sight ... a Blackbird with no tail. I took this photo through my mother's kitchen window about a month ago and today she confirmed that this individual is still visiting her garden. So the lack of tail feathers does not appear to be impeding its survival.
All indications are that he is going through his normal post breeding moult but it doesn't explain the total lack of a tail but there is the possibility that one of the local felines might be feeling guilty!
I'll try to see what shape he is in now when I visit my parents tomorrow.