I have been keeping weekly records of maximum counts of each species seen in the garden for over eleven years. This is to provide data for the British Trust for Ornithology as part of their Garden Birdwatch scheme to track changes in bird populations through the weeks and years.
For our garden, the most notable change during that time has been the number of greenfinches coming to the feeders. In the last week in January in 2009 there were a maximum of thirteen greenfinches recorded. In 2010 it was ten. In 2011 this went down to two. Since then the number has usually been zero in that week including this year and last year. The greenfinch population has been hit by a disease called trichomonosis which started to affect them around 2005.
Sadly, the last greenfinch I saw on our feeders, was almost immediately caught by a passing sparrowhawk, an increasingly frequent garden visitor at the moment.