A quick note from the UK - beware of taking the numbers of people who belong to
the RSPB as a measure of the number of birders. The RSPB is not a "birding
club" - it is a bird conservation organisation and one of its prime functions
is to acquire and manage habitat as reserves. These reserves are usually
managed to make them very accessible to visitors, and provide a good day out
for anybody more-or-less interested in birds. The annual membership fee is not
large and provides free access to many reserves, and a good glossy magazine, so
membership has a financial benefit. Many RSPB members would not describe
themselves as birders.
The RSPB also runs local groups, which are much more like clubs, but again are
not really aimed at the serious birder - more the "garden birdwatcher".
"Serious birders" often do not belong to clubs at all (many do not even belong
to the RSPB which is pretty disgraceful), or belong to local clubs. For
instance, we belong to the Pembrokeshire Bird Club (though this is a recent
thing for us, not being very clubby people). But these clubs are finding it
difficult to keep up membership, for all the reasons mentioned in previous
mails. Basically you no longer need to go to a club to find out what's going in
the area, which you probably did have to do only 10 years ago.
In the UK we also have the BTO (British Trust for Ornithology) with 13, 000
members. This organisation carries out a huge amount of scientific fieldwork,
principally using volunteers. However, many of the volunteers who do the survey
work are not members so the membership figures are again not really useful!
In summary I would say that there is indeed a high level of general interest in
birds in the UK, and in wildlife and conservation issues in general, but there
are probably not as many serious birders as the figures might suggest.