bird lists

[Dave Hanscom <hanscom at cs dot utah dot edu>]

I'm a relative newcomer to this list, and a much less experienced birder
than many of you who post messages.  I'm hoping that someone can answer a
rather elementary question.

Occasionally someone will mention a sighting of a bird that I don't find
in my bird books.  I've also learned that bird species lists aren't static
from year to year.  Sometimes species are combined, and sometimes they're
split.  My question is - where can I find the latest accepted list of
different bird species?

Thanks much.

Dave Hanscom