Gaby
Dolphins are among the planet’s smartest animals — and female bottlenose dolphins apparently use a kind of “baby talk” with their calves. Recent studies show these animals share similarities with humans not just in intelligence but in how they behave around their young. Female dolphins communicate with their calves differently than they do with adults: much like humans use high-pitched baby talk with toddlers, bottlenose dolphins alter their usual whistles when interacting with offspring.
The Maternal “Language” of Dolphins
Marine biologist Laela Say and her team analyzed the whistles of 19 female bottlenose dolphins, both when the mothers were with calves and when they were alone or with other adults. The team used audio recordings of a wild population near Florida collected during health assessments under a catch-and-release program from 1984 to 2018. They found that mothers consistently produced whistles with higher maximum frequencies and a wider frequency range when their calves were present than when calves were absent. Say and her colleagues say this change helps mothers get their calves’ attention, strengthens the mother–calf bond, and helps calves learn vocal patterns the way baby talk helps human children learn to speak.
Across human cultures, child-directed speech is nearly universal. Animal examples are rare, though; as the Daily Mail reported, researchers have previously observed different calls for adults and young in some monkey species and in zebra finches. Bottlenose dolphins are especially interesting because each dolphin develops a unique melody, or signature whistle, during the first few months of life.
Say points out that dolphins essentially call out their own “names” in the water to keep track of one another. Mother dolphins modify this signature whistle when calves are nearby; calves typically stay close to their mothers for three to six years. Say first noticed this pattern in 2009 during a student’s research project, which led to more focused study. Her recent work highlights a pattern similar to human parent–child communication: long-lasting mother–calf bonds and lifelong vocal learning. The calves in the study averaged about two years old, a timeline that matches the age range for child-directed communication in humans.
The mothers’ “baby talk” appears to speed up calves’ ability to produce their own whistles. Say suggests that by imitating the sounds of a smaller vocal tract, adults guide calves in how to form their own sounds.
Vocal Data is Vital for Bottlenose Dolphins
Dolphin whistles also play a role in courtship and mate choice. Dolphins use vocalizations to attract partners and to compete for mates. Vocal exchanges can boost a dolphin’s social popularity, helping maintain looser but important social ties across the group. More socially popular males tend to have greater mating success and more offspring, so learning vocal skills as a calf has clear long-term benefits.
Marine mammal behavior ecologist Quincy Gibson says bottlenose dolphins are prime candidates for child-directed communication because they form strong mother–child bonds and learn vocalizations over their lives. Gibson adds that to fully confirm Say’s findings, researchers still need to analyze mothers’ signature whistles directly in the wild.
