I used to think whale songs were just—well, songs.
Turns out, sperm whales don’t really sing at all. They click. They produce these rapid-fire percussive bursts called codas, sequences of clicks that sound less like music and more like someone tapping out Morse code on a wooden table underwater. And here’s the thing: different groups of sperm whales—clans, researchers call them—use completely different clicking patterns, almost like they’re speaking distinct dialects. It’s not just variation; it’s systematic difference. A whale from one clan in the Caribbean produces codas that a whale from another clan in the same ocean wouldn’t recognize or use. These aren’t just individual quirks. They’re cultural markers, passed down through generations of female whales who stick together for life, teaching their young the specific rhythm and tempo of their clan’s identity. Honestly, when I first read about this, I thought maybe scientists were overinterpreting the data—whales clicking differently, sure, but dialects? That felt like anthropomorphizing. But the evidence is pretty overwhelming now.
We’re talking about patterns that remain stable across decades, maybe centuries. Some clans have been tracked since the 1980s, and their coda repertoires haven’t changed. The whales learn these from their mothers and aunts, not from their fathers—sperm whale society is matrilineal, with males leaving their birth groups around puberty to wander alone or in bachelor pods.
The Clicking Grammar That Divides Ocean Neighborhoods
Each clan has what researchers call a “coda repertoire”—a set of rhythmic patterns they use regularly. One clan might favor a “1+1+3” pattern (one click, pause, one click, pause, three rapid clicks). Another prefers “2+3” or “4+1”. There are at least seven distinct clans identified in the Pacific alone, each with its own signature style. Wait—maybe style isn’t the right word. It’s more like a passport stamp, an auditory flag that says, “I belong to this group.” The clans don’t seem to interbreed much, even when they occupy overlapping ranges. They definately keep to their own kind. Researchers think the dialect itself might function as a social boundary, a way of maintaining group cohesion and identity across vast stretches of ocean where visual cues are useless and scent doesn’t travel far.
And the complexity doesn’t stop there. Within a single coda type, whales modulate the tempo—slightly faster, slightly slower—which might convey additional information. Context matters too. Some codas appear during socializing, others during deep dives when the whales are hunting squid in the pitch-black abyss two kilometers down. I guess it makes sense that a species spending most of its life in darkness would evolve such a sophisticated acoustic culture, but the specificity of it still catches me off guard every time I dig into the research.
When Scientists First Started Actually Listening Underwater
The breakthrough came in the 1980s when marine biologist Hal Whitehead and his colleagues began systematically recording sperm whale clicks in the Caribbean and Pacific. Before that, we knew whales made sounds, but we didn’t realize the sounds had structure, let alone cultural transmission. Early hydrophone recordings were patchy and hard to analyze—this was before digital signal processing made it easy to visualize sound patterns. Whitehead’s team spent years cataloging thousands of hours of recordings, painstakingly identifying individual whales by the unique features of their clicks (every whale has a slightly different voice, like a fingerprint made of sound). Slowly, patterns emerged. Whales that traveled together used the same codas. Whales that didn’t travel together used different ones.
The term “clan” came later, borrowed from anthropology, because the social structure mirrored human kinship systems more than anyone expected. These weren’t just random groups—they were multi-generational lineages with shared traditions.
Why Some Clans Thrive While Others Fade Into Acoustic Silence
Here’s where it gets messy. Not all clans are equally successful. Some are abundant, with hundreds of members spread across thousands of square kilometers. Others are small, maybe a few dozen individuals, their dialects heard less and less frequently in hydrophone surveys. We don’t entirely know why. It could be environmental—some clans might specialize in hunting techniques that work better in certain regions or during certain oceanographic conditions. It could be social—maybe some dialects make it easier to coordinate group hunting or defend calves from orcas, which are one of the few predators that attack young sperm whales. Or maybe it’s just demographic luck, random population fluctuations amplified over time. Whale populations were decimated by commercial whaling in the 20th century—sperm whales were hunted by the hundreds of thousands—and it’s possible entire clans were wiped out, their dialects lost forever before we even knew they existed. The whales alive today are the descendants of survivors, and their acoustic cultures reflect that bottleneck.
The Uncomfortable Question of Whether Whales Have Something Like Language
Nobody wants to say “language” outright, because that word carries so much baggage. Language implies syntax, grammar, the ability to recombine elements to generate infinite novel meanings. Sperm whale codas don’t seem to do that—they’re more like fixed phrases, repeated in specific social contexts. But then again, we’ve only been studying this seriously for about 40 years, which is nothing compared to the millions of years sperm whales have been clicking at each other in the deep. Maybe we just haven’t cracked the code yet. Recent machine learning studies have started analyzing coda sequences for hidden patterns, looking for rule-based structure that human ears might miss. Preliminary results suggest there might be more going on than simple repetition—possible evidence of combinatorial rules, though the data is still too limited to say for sure. Anyway, whether it’s language or not, it’s definately communication with cultural transmission, and that alone puts sperm whales in a very small club of species that teach their young how to sound like their group. Elephants do it. Some songbirds do it. Humans do it. And sperm whales, clicking in the dark, do it too.
What Happens to Dialects When Clans Meet in the Open Ocean
Sometimes different clans cross paths. When they do, they don’t usually interact much—they seem to recognize that the other group “sounds wrong” and keep their distance. But occasionally, researchers have recorded mixed groups, whales from different clans traveling together temporarily, possibly because they stumbled onto the same rich feeding ground. In those moments, do they try to communicate? Do they code-switch, adjusting their clicking patterns to accommodate the other dialect? We don’t know. The recordings are too sparse, the encounters too brief. What we do know is that young whales are occasionally observed producing codas that don’t match their clan’s repertoire—mistakes, maybe, or experiments, like a child mispronouncing a word. Usually, they grow out of it and conform to the group norm. But every now and then, a new coda variant sticks around, gets picked up by others, and slowly becomes part of the clan’s repertoire. Cultural evolution in real time, happening at the pace of whale generations, too slow for us to watch directly but fast enough that we can see the evidence in longitudinal data. It’s humbling, really. We think of culture as a human thing, but these whales have been cultivating their acoustic traditions since before our ancestors figured out stone tools. And we’re only just starting to listen.
