Incidentally, the author doesn’t comment on US Southern prestige accents that were non-rhotic almost from the start. The reason for that? They were raised by their black nannies and African languages are non-rhotic. Southerners hate to hear this, but their prestige non-rhotic plantation accents are the product of slave speech!
Are you sure about that? Does "rhotic" vs "non-rhotic" even have any meaning outside the context of English?
Frinstance a non-rhotic accent isn't about not being about to say "er". A non-rhotic speaker will say, frinstance "her father" with an "err" sound on "her" and an "a" sound on "father".
I know it occurs in German between southern and northern accents where the r at the end of words is silenced in the north. I'm sure it occurs in other languages too.
I think you're confusing vowel shifts with rhotacism. A non-rhotic speaker will not pronounce the r in either "her" or "father". It's quite possible the vowel shift at the end of father happened in response to the disappearance of the rhotic r, but it is a separate effect.
Actually I think you're right. I don't actually pronounce an "r" sound at the end of "her", I just use a different non-r vowel from the one I use for "father". Never mind, I take it back.
I'm still skeptical about rhoticity in African languages.
That is probably what he meant when he gave his own, strogly non-rhotic pronounciation of "err" as an example for how people might pronounce "her". But without everybody knowing how to read and type IPA, you can't be to sure about anything in discussions about phonetics.
I'm sure that this is what Rocco said, and of all people in the world, he's in the best position to know for sure. If you have questions, I suggest e-mailing him using the address on his site, which I linked above.
Are you sure about that? Does "rhotic" vs "non-rhotic" even have any meaning outside the context of English?
Frinstance a non-rhotic accent isn't about not being about to say "er". A non-rhotic speaker will say, frinstance "her father" with an "err" sound on "her" and an "a" sound on "father".