"This is a hidden list, which means that the list of members is available only to the list administrator.” Reason for this policy is protection of members’ privacy.
As of this moment the list has 3,447 subscriptions. However, this number is higher than the true number of subscribers, for two reasons: 1) Some members have more than one subscription; and 2) The list contains an unknown number of effectively dead addresses. This happens, for example, when a subscriber abandons an e-mail account but neglects to cancel his/her subscription to Tweeters. The listserver can detect this if messages bounce back from a disabled account, and in such cases automatically removes the subscription. But if that account has been set to “nomail”, which suspends the delivery of messages, then the server receives no feedback has no way of knowing whether the address is a valid one or not. Thus the actual number of subscribers cannot be accurately determined.
On the other hand, an unknown but presumably high number of non-subscribers consult Tweeters regularly online. The messages are posted in real time to the Tweeters archives at http://mailman1.u.washington.edu/pipermail/tweeters/. The most recent postings (a month’s worth, more or less) may also be consulted on the American Birding Association website at http://birding.aba.org , and at least one other website I believe.
Hal Opperman (pinch hitting for Dan Victor)