Leopard seals, some of the most solitary creatures in Antarctica, surprise us with their unique behavior. A recent study shows these large predators spend hours underwater singing songs that resemble the nursery rhymes we share with children.
Researchers at UNSW Sydney analyzed recordings of leopard seal calls. They found that the structure of these songs shares similarities with human rhymes. Lucinda Chambers, the lead author, noted that the patterns in their songs show a level of predictability close to our own childhood tunes.
Interestingly, these seals aren’t singing lullabies for pups. Male seals do most of the vocalizing, and their songs relate more to competition and courtship than parenting.
Springtime Serenade
Leopard seals thrive in the frigid waters around Antarctica, usually living alone. However, from late October to early January, this changes. Male seals embark on a daily ritual, swimming under the ice and singing for hours. They alternate between staying underwater for two minutes and surfacing for two minutes—a serious commitment, with some seals singing for up to 13 hours daily.
Professor Tracey Rogers, a co-author of the study, began capturing these songs in the 1990s. “They’re like the songbirds of the Southern Ocean,” she says. Drop a hydrophone into the water, and you’ll hear them singing everywhere.
Unique Sounds with a Purpose
These calls aren’t just random noise. Each seal’s song has five core sounds, but the magic lies in how they arrange them. As Professor Rogers explains, it’s not about the sound itself but the order that makes each seal’s song unique.
The calls can travel long distances, which is vital during the brief breeding season when females are in heat for just a few days each year. Chambers highlights that the structure in their songs helps ensure that distant listeners can clearly identify the singer.
Male seals use these songs not only for attracting mates but also for marking territory. It’s a dual message—proclaiming their strength to potential partners while warning rivals to stay away.
A Close Comparison
To understand how leopard seal songs stack up against other vocal animals, researchers compared their calls to those of humpback whales, dolphins, and different styles of human music. Surprisingly, they found that leopard seal songs closely resemble nursery rhymes. Chambers points out that both share qualities of simplicity and memorability—a sweet blend of uniqueness and structure.
Signature Sounds
The past recordings in the study came from the 1990s when Professor Rogers would bike across Antarctica to mark individual seals and gather their songs at night. Each male seal uses the same five sounds, but the order creates a sort of “signature” for each seal. Chambers compares this to names, where each seal’s pattern is distinctive.
Looking to the Future
As technology advances, researchers plan to return to Antarctica to see how these songs may have evolved. Chambers wants to explore whether new call types have emerged and if the sound patterns shift from generation to generation.
In some of the coldest, quietest places on Earth, animals like the leopard seal are still finding unique ways to communicate and be remembered.
You can read the full study in the journal Scientific Reports.
