This is a problem with multiple common names. The ufg application is
capable of displaying up to 8 common names per species. However, I
intentionally didn't transfer the alternate common names in the class
database when the AOU last updated its list because it isn't clear
that enough people use the feature to warrant the work of transferring
the common names (which is not yet automated). If users want this
feature enabled, they should let me know. So far, you are the first
to mention anything about the lack of alternate common names.
The AOU's common name for the Rufous-sided Towhee is the Eastern
Towhee.