I pulled up some Christmas bird count data for Townsend's
Warbler and Orange-crowned Warbler. While annual fluctations,
most probably associated with climatic conditions, are expected
the 30 year trend shows a rather dramatic increase which is
more probably an artifact of observer awareness.

http://home.pacifier.com/~neawanna/neotrops/cbcwarb.html

--
Mike Patterson When I despair, I remember
Astoria, OR that all through history
celata at pacifier.com the way of truth and love have always won.
There have been tyrants, and murderers,
and for a time they can seem invincible,
but in the end they always fall.
Think of it...always.
- Mahatma Gandhi

http://www.pacifier.com/~mpatters/bird/bird.html