"Dolphin Mothers Employ Infantile Language when Communicating with Offspring"

When communicating with young children, humans often use a high-pitched, baby-talk tone. Surprisingly, some dolphins use a similar tactic, according to a report from researchers in the Proceedings of the National Academy of Sciences on June 26th. Among bottlenose dolphins, mothers will adjust their distinctive whistles when their calves are nearby. This change, known as parentese, is thought to enhance bonding, attention, and vocal learning within baby dolphins, just as it does in infant humans.

A common bottlenose dolphin (Tursiops truncatus) develops a unique tune during the first few months of life, called a signature whistle – somewhat equivalent to a name. The whistle allows the dolphins to keep track of one another, says marine biologist Laela Sayigh from Woods Hole Oceanographic Institution in Massachusetts.

Even more interestingly, dolphin mothers tend to change their signature whistle in the presence of their calves. During the period when offspring are near to their mothers, on average, the dolphins’ maximum whistle pitch is higher and the minimum pitch is slightly lower than what is routinely heard. The pitch range is also increased – much like the expanded pitch range humans exhibit when speaking in parentese.

According to Quincy Gibson, a marine mammal behavioural ecologist who was not involved with the study, "Bottlenose dolphins are a prime candidate for child-directed or calf-directed communication. Similar to humans, these dolphins form strong mother-baby bonds and learn vocalisations."

While nobody can yet confirm if dolphin and human parentese share the same functions, the concept that these two species may showcase similar parenting forces is fascinating.