Blue Tit ( Cyanistes caeruleus )

This just had to be today's blip.  I have never seen a Blue Tit coloured like this one.  The colouration suggests it is a partial leucistic specimen.  Leucism is a genetic condition that inhibits the production of pigments particularly melanin in parts or all of the body.

The opposite of Leucism is Melanism.  I have seen this a few times but only in Pheasants.  They appeared from a distance black closer to they had lovely iridescence.  

I have included an extra of a "normal" Blue Tit for comparison.