I've been suffering from the same lack of birds in my yard this fall.  Do we
think it's directly related to Irene? I have had a few, very few, Hairy and
Downies, a handful of resident Chickadees, a few nuthatches, a small number
of Blue Jays, but a WHOLE MEss of crows.   There is a "flock" of at least a
hundred,  I would say,  that has been gathering VERY loudly in my
neighborhood for the last few weeks at least.