In reply to djwilse:
Some of us like to watch birds, like to see new (for us) species, like to record and keep track of what we've seen. Bit similar to most of us keeping climbing logs to remember what we've done.
Others are obsessed with lists, how many species they've seen in the UK (ever), how many each year, county lists, garden lists, etc, etc. Often these obsessives are not that interested in actually watching the birds, how they behave, etc. Got the tick, what's next. Much more like climbers who become obsessed such that grade chasing becomes the focus rather than the enjoyment of moving over rock, getting to nice locations etc.
Obsessive twitchers will drive hundreds of miles to get an extra "tick". Paparazzi for birds is a great description of the phenomenon.
Post edited at 09:26