Baby humpback whale begs its mother for milk with burps and cries

Hear how baby humpback whales burp and bark as they beg for food

Written by Jack Tamisia

A newborn humpback whale can be over 15 feet long from nose fluke to tail fluke and weigh as much as a full-grown giraffe. But these stocky calves need to gain weight quickly to approach their parents’ even more impressive proportions. Each day, humpback whale calves drink hundreds of liters of milk, which is as thick as toothpaste and rich in fat.

And just as a human baby shows off its amazing lung capacity when it’s hungry, a baby humpback whale makes its mother’s voice heard when it wants milk. According to a new study published Wednesday, Proceedings of the Royal Society B: Biological Sciencesa hungry humpback whale calf emits a low-frequency call to signal its nutritional needs. These noises, which sound like burps, barks, and snorts, are the first recorded examples of begging-like behavior in baleen whales.

About supporting science journalism

If you enjoyed this article, please consider supporting our award-winning journalism. Currently subscribing. By subscribing, you help ensure future generations of influential stories about the discoveries and ideas that shape the world today.

Humpback whales have an impressive vocal repertoire, which helps them communicate over long distances and through murky waters. Adult males compose unforgettable songs to charm their companions. And all humpback whales make less structured calls that they use in a variety of social situations.

Scientists have been studying these calls for decades, but relatively few studies have focused on the vocalizations between humpback whale calves and their mothers, says a bioacoustics researcher. , said study lead author Maevatyana Ratsimbazafindranahaka, who conducted the research as a doctoral student at the Paris-Saclay Institute of Neuroscience. In France. This obscures key aspects of humpback whale social upbringing. “These early interactions may play an important role in shaping humpback whale social behavior, including after weaning,” he says.

To hear about these interactions, Ratsimbazafindranahaka teamed up with Malagasy researchers to find humpback whale calves swimming near the island of Sainte-Marie, also known as Nosy Boraha, along the whale migration route. The cows were investigated. The research team fitted eight humpback whale calves with video cameras and hydrophones (devices that record their vocalizations). Back at the lab, the scientists reviewed the approximately 33 hours of recordings and isolated the calf’s vocalizations. They then synchronized the calls with various behaviors exhibited by the calves during the corresponding videos, such as playing, moving, and resting.

Researchers identified more than 500 social calls among whale calf cadres, and found that calves are mostly silent during activities such as resting and migrating, and more noisy while playing. I discovered something new.

The baby whales were especially noisy before nursing. On average, breastfeeding sessions produced the most cries of any behavior the team studied. These vocalizations were typically low-frequency burps, barks, snorts, and growls, which surprised the researchers. “We expected young animals to use high-pitched calls to communicate their needs,” Ratsinbazafindranahaka says.

Researchers hypothesize that calves use these rumbling sounds to beg their mothers for milk. Anyone with a pet dog is familiar with begging, but this behavior is common throughout the animal kingdom and can be seen in everything from beetles and poison dart frogs to fledgling birds. . Other marine mammals, such as bottlenose dolphins and Araguayan river dolphins, also exhibit begging-like behavior.

Ratsimbazafindranahaka says humpback calves are likely not the only whales singing for milk. He predicts that other baleen whales also exhibit begging-like behavior, although the components of their vocalizations are different. For example, baby blue whales, because of their incredible size, can signal their hunger with even lower-frequency rumbling sounds. A newborn blue whale weighs more than twice as much as a baby humpback whale.

Julia Zeh, a research biologist with the National Oceanic and Atmospheric Administration who studies humpback whale acoustics, said humpback whales have a vast vocal repertoire, making it difficult to link their calls to specific behaviors. But she believes the new findings will help improve our understanding of how these whales communicate during critical periods in their lives.

Detailing the intricacies of mother-calf communication highlights how these creatures are threatened by human disturbances such as shipping and seismic surveys that increase ocean noise. “For whales to survive, they need to be able to hear each other and communicate effectively,” Zee said.