The importance of commonplace

After yesterday's perusal of the unusual, I found myself looking out of the kitchen window with a renewed marvel of the birds that I see every day and too often pass over because of their familiarity to me. Chaffinches are pretty well everywhere and at this time of year I tend to almost ignore them in the hope of spotting the rather less common Brambling that turn up here most winters (none yet this year). However in recent years my chaffinch flock (ok, they aren't mine really) have been quite badly by afflicted by a disease called bumblefoot. I don't really know quite how badly this unsightly disease affects breeding success or mortality rate but so far this year it has hardly been in evidence here which I assume is a good thing. Anyway, what stunning birds they are, perfectly designed seed eaters, beautiful colours even in the middle of winter, great opportunists and born survivors which should never be overlooked.
It was -7C last night and barely struggled above freezing yet again today so its certainly the sort of weather that our Scandiavian visitors, the Redwings, should be at home in. Sure enough, after my previous post dismissing them, they returned in force today and seemed to be stood in trees all over the place. They always remind me of a photograph proudly shown to me years ago of a Redwing, a Blackbird, a Mistle Thrush, a Song Thrush and Fieldfare in perfect formation in the snow feeding on something he had put out. On questioning he revealed his secret bait as tinned pears, something he said was irresistable to thrushes, but something I have never quite brought myself to try out. Maybe tomorrow.
One bit of behaviour I do not quite understand at the moment is why the Blackbirds, while tolerant of eachother, continually drive off any visiting Song Thrushes. Answers on a postcard please..