Scientists have found that bottlenose dolphin mothers tend to communicate differently with their young, much like human mothers and other caregivers do.
This “motherese,” also referred to as child-directed communication (CDC), has an acoustic signature that includes higher pitch and wider pitch range, and is thought to promote attention, bonding and language acquisition in children.
Bottlenose dolphins appear to similarly modify their communication signals when with their calves.
An analysis of recordings made during brief catch-and-release events of wild bottlenose dolphins in waters near Sarasota Bay, Florida, found that females produced signature whistles with significantly higher maximum frequencies and wider frequency ranges when they were recorded with their own dependent calves vs. not with them, according to a paper written by scientists from the Woods Hole Oceanographic Institution.
Co-lead author Laela Sayigh, a biologist at WHOI, said:
“It’s really exciting to find evidence for CDC in another mammalian species, even if we can’t necessarily speak to its function in dolphins. The fact that dolphins use motherese is an excellent example of what we call convergent evolution. That is, a similar type of communicative strategy has evolved in three very different species – humans and dolphins, as well as zebra finches. This is certainly suggestive of the idea that motherese probably serves some function, though we are not in a position to test that.”
Check out the paper here.