Great Tit

I thought it only right to follow the blue tit with its close relative and another familiar friend, the great tit or Parus major. Not the best photo but you get the idea. (Special prize for identifying the other bird on the feeder!)
  
They are not quite as common as blue tits, but more prolific breeders, with most pairs raising two broods every year and laying larger clutches (around ten eggs). Unlike the blue tit they are visibly dimorphic to humans, the males having an unbroken black band down the middle of the abdomen with an obvious broadening, whereas the females have a narrower band which is often discontinuous lower down.

There are fourteen recognised subspecies of great tit, and the one in Britain is Parus major newtoni. The nominate subspecies is (of course) Parus major major (cf. 'Catch 22') as this was the one first described when the species was identified. P. m. newtoni had a broader stripe than P. m. major. 

The definition of what the terms subspecies and races are are very particular and yet somehow also rather vague. At the end of the day is a matter of arbitration by a group of 'experts'. And the situation is even more complicated in botany where there exists further divisions into strains and forms. Mr Bryson refers to the tendency of scientists to be 'splitters' or 'lumpers' (see book list) and I must say that for the generalist amateur, lumpishness is very much the order of the day (excuse the pun).

Now great tits do have one of the more recognisable calls of our common birds, classically described as "tea-cher" and often repeated. But they are notorious for the variety of calls and songs in their repertoire.