Yesterday, new evidence on the nature of sperm whale social vocalisations (their coda) was published in Nature Communications. It showed that neither genetics, nor learning from the mother, nor learning from others in the region, nor any combination of these three factors, was sufficient to explain the observed pattern of ‘dialect’ distribution in the South Pacific. Additional factors had to be invoked that shadowed the nature of culture and cultural identity as we know it in humans. Here is one commentary on this matter.
What they don’t comment on is that these patterns would form more readily still if these ‘dialects’ were not dialects at all, but completely separate languages. Perhaps, one day, they will investigate that possibility too.