Leopard seals might not be the first animal that comes to mind when we think about singing, but new research suggests their songs may have more in common with us than we ever imagined. A study published in Scientific Reports found that the underwater singing of male leopard seals in Antarctica shares a remarkable structural similarity to the nursery rhymes humans sing to children.
Using data from analog recordings collected in the 1990s, researchers analyzed the calls of 26 individual male seals. They discovered that these solitary apex predators don’t just sing randomly, but follow a predictable, repetitive structure made up of five key sounds. While these calls are shared across a population, each male arranges them in his own distinct order, creating a unique sonic “name.”
“Leopard seal songs have a surprisingly structured temporal pattern,” said Lucinda Chambers, lead author of the study and Ph.D. candidate at the University of New South Wales, in a press release. “When we compared their songs to other studies of vocal animals and of human music, we found their information entropy — a measure of how predictable or random a sequence is — was remarkably close to our own nursery rhymes.”
Why Do Leopard Seals Sing?
Each spring, male leopard seals begin a rigorous and highly vocal routine across the Eastern Antarctic pack ice. They sing solo underwater for up to 13 hours a day, diving in and out of the sea in rhythmic two-minute cycles: two minutes submerged singing, followed by two minutes above water for air, repeatedly. But unlike human nursery rhymes, the leopard seal tunes aren’t meant to soothe children to sleep.
The study suggests that singing plays a key role during the short breeding season. Female leopard seals are only fertile for four or five days a year, and while they may sing briefly during this time, they’re surrounded by the nonstop choruses of males vying for attention. The vocalizations are likely tied not just to mating, but also signaling dominance, fitness, or even individual identity.
“They’re incredibly committed. They’re like the songbirds of the Southern Ocean,” said Tracy Rogers, co-author and professor at UNSW, in the press release. “You can’t tell them apart by how the call sounds. It’s the order and pattern that matters. They’ve stylized it to an almost boring degree, which we think is a deliberate strategy, so their call carries a long distance across the ice.”
Read More: Here's Why Dolphins Have to Shout Underwater
Comparing Seal Songs to The Beatles
To better understand these songs, researchers measured their structure and compared them to vocal patterns from humpback whales, dolphins, squirrel monkeys, and different styles of human music from classical to The Beatles. What stood out was the songs’ similarity to nursery rhymes.
“Nursery rhymes are simple, repetitive, and easy to remember — that’s what we see in the leopard seal songs. They’re not as complex as human music, but they aren’t random either. They sit in this sweet spot that allows them to be both unique and highly structured,” said Chambers in the press release.
The next phase of the team’s research will involve mathematical modeling to determine whether these underwater arias act as true vocal signatures like the whistles used by bottlenose dolphins. Additionally, they hope to learn more about the evolution and passing down of these songs between generations of leopard seals.
“We want to know if new call types have emerged in the population. And if patterns evolve from generation to generation,” said Chambers in the press release. “We’d love to investigate whether their ‘alphabet’ of five sounds has changed over time.”
Read More: Are Leopard Seals as Dangerous as You Think?
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Scientific Reports. Leopard seal song patterns have similar predictability to nursery rhymes
As the marketing coordinator at Discover Magazine, Stephanie Edwards interacts with readers across Discover's social media channels and writes digital content. Offline, she is a contract lecturer in English & Cultural Studies at Lakehead University, teaching courses on everything from professional communication to Taylor Swift, and received her graduate degrees in the same department from McMaster University. You can find more of her science writing in Lab Manager and her short fiction in anthologies and literary magazine across the horror genre.
