Below is a link to an article in one of the recent CBC summary issues that
shows how modern statistical methods can be used to make some sense of messy
CBC data. Each CBC summary issue now has a number of articles by wildlife
biologists using the CBC database for various (usually conservation related)
purposes.

Article -
http://www.audubon.org/bird/cbc/pdf/104_021-25ANALYSISfeature.pdf

CBC summary issues can be selected from the drop down box near the bottom of
the main CBC web page:
http://www.audubon.org/bird/cbc/index.html

--
Charles Swift
Moscow, ID
chaetura at gmail.com