You may read up-to-the-minute postings for both lists as well as all earlier ones back to 1999 by visiting the Archives pages :
For Tweeters : http://mailman1.u.washington.edu/pipermail/tweeters/
For Tweeters-Alerts : http://mailman1.u.washington.edu/pipermail/tweeters-alerts/
The list archives are accessible to the public. No login is required. Archives are grouped by month and year. They may be read online or downloaded. An online search engine is provided.
You may also read the most recent postings, courtesy of ABA Birding News, at :
For Tweeters : http://birding.aba.org/maillist/WA
For Tweeters-Alerts :