The only link apparent in discography was Donald's Byrds Word and three years on, Charlie's Byrds Word!. Yet it seems they never played together in the same session as never did Charlie's brother Joe Gene Byrd (not to be confused with the more avant garde Joseph Byrd). Neither are we sure on the lineage of Eric Byrd from the well known Eric Byrd trio. There was a distinct difference in styles too, Charlie was a guitarist and arranger with a Latin bent, Donald was ubiquitous in his many ensemble and band appearances as a saxophonist.
There is a long list of other musical Byrds such as Professor Longhair, Bobby Byrd, Jerry Byrd, Jonathan Byrd, Steve Byrd, Winston Byrd, and even Toni Byrd. Again, all from completely disparate styles of music.
Fans/Googlers may also be familiar with the band, The Byrds whose name does not relate to anything related to jazz at all, (if that were ever the case, could have The Yardbirds from the year before been part inspiration?)
Even though the name of Byrd is rare in some parts of the world compared to the U.S, (from where most of the above-mentioned Byrds emanate), can we ever assume the name applies more to musicians than not?