Sperm Whale Sounds, Communication and Intelligence | Sea Life, Islands and Oceania

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SPERM WHALE INTELLIGENCE USED TO OUTWIT WHALERS

20120521-Whaling Walfang_zwischen_1856_und_1907.jpg
whaling in the late 18th and early 20th century
Sara Novak wrote in Discover: When it comes to brains, is size all that matters? There’s a lot we don’t know about sperm whale intelligence because it’s difficult to carry out neurological testing on a marine mammal of this magnitude. But some clues point to sperm whales being much smarter than we give them credit for. [Source:Sara Novak, Discover, November 19, 2022]

A March 2021 study published in Biology Letters looked back to 19th-century historical logbooks from whalers. Researchers found that sperm whales were at first easy to catch — but almost immediately, the whales learned how to evade hunters and whaling success plummeted by 60 percent. The study hypothesizes that the whales passed information to one another through echolocation to avoid being caught.

Business Insider reported: “The study's authors, cetacean researchers Professor Hal Whitehead and Dr. Luke Rendell, as well as data scientist Dr. Tim D Smith, found that the strike rate of the whalers' harpoons fell by 58 percent in less than two and half years after they first began hunting in the region. In Halifax, Canada, Professor Whitehead of Dalhousie University told The Owen Sun Sound Times: "That was very remarkable. I thought there might be a drop, but not that much and not that quickly. “Usually, you expect it to increase as they figure out stuff and become more successful. That's typically how our exploitation of wildlife goes. We become more efficient as we learn how to do it." [Source: Naina Bhardwaj, Insider, March 20, 2021]

“The study concluded that sperm whales had learned how they were being killed, shared this information with their pod and changed their behavior accordingly, displaying 'cultural evolution.' The species live with their children in female-only pods or groups, allowing them to form close links and share tips to evade hunters. The hunters recognized the sperm whales had developed tactics to evade them. Instead of forming defensive squares used to fight off their natural predators, the killer whale, the sperm whales, understood that swimming against the wind would allow them to outrun the wind-powered hunters' ships.

Websites and Resources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Fishbase fishbase.se; Encyclopedia of Life eol.org; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems ; Monterey Bay Aquarium montereybayaquarium.org ; MarineBio marinebio.org/oceans/creatures

Sperm Whale Sounds

sperm whale using echolocation to locate a giant squid
Sperm whales use clicking noises for echolocation (emitting sound waves and sensing their reflections to determine the location of objects), but they also make a variety of other sounds including "groans, whistles, chirps, pings, squeaks, yelps, and wheezes". Their voices are quite loud and can be heard many kilometers away with underwater listening devices. Each whale also emits a stereotyped, repetitive sequence of 3-40 or more clicks when it meets another whale. This sequence is known as the whale's "coda." [Source: Liz Ballenger, Animal Diversity Web (ADW)]

Eric Wagner wrote in Smithsonian magazine: In 1839, in the first scientific treatise on the sperm whale, Thomas Beale, a surgeon aboard a whaler, wrote that it was “one of the most noiseless of marine animals.” While they do not sing elaborate songs, like humpbacks or belugas, in fact they are not silent. Whalers in the 1800s spoke of hearing loud knocking, almost like hammering on a ship’s hull, whenever sperm whales were present. They called the animals “the carpenter fish.” Only in 1957 did two scientists from the Woods Hole Oceanographic Institution confirm the sailors’ observations. Aboard a research vessel, the Atlantis, they approached five sperm whales, shut off the ship’s motors and listened with an underwater receiver. At first, they assumed the “muffled, smashing noise” they heard came from somewhere on the ship. Then they determined the sounds were coming from the whales.[Source: Eric Wagner, Smithsonian magazine, December 2011]

How Sperm Whale Make Sounds

It is believed to that sperm whale sound is produced in the “lips” in the nasal passages near the blowhole; magnified in spermaceti’s organ’s case and focused into a beam by the jun. After that the sound bounces off the back of the skull and then down and out the front of the head. When the sound emerges it has been focused to about the width of a telephone pole.

Eric Wagner wrote in Smithsonian magazine: Biologists now believe that the sperm whale’s massive head functions like a powerful telegraph machine, emitting pulses of sound in distinct patterns. At the front of the head are the spermaceti organ, a cavity that contains the bulk of the whale’s spermaceti, and a mass of oil-saturated fatty tissue called the junk. Two long nasal passages branch away from the bony nares of the skull, twining around the spermaceti organ and the junk. The left nasal passage runs directly to the blowhole at the top of the whale’s head. But the other twists and turns, flattens and broadens, forming a number of air-filled sacs capable of reflecting sound. Near the front of the head sit a pair of clappers called “monkey lips.” [Source: Eric Wagner, Smithsonian magazine, December 2011]

Sound generation is a complex process. To make its clicking sounds, a whale forces air through the right nasal passage to the monkey lips, which clap shut. The resulting click! bounces off one air-filled sac and travels back through the spermaceti organ to another sac nestled against the skull. From there, the click is sent forward, through the junk, and amplified out into the watery world. Sperm whales may be able to manipulate the shape of both the spermaceti organ and the junk, possibly allowing them to aim their clicks. The substance that made them so valuable to whalers is now understood to play an important role in communication.

World’s Loudest Animal: Sperm Whale or Blue Whale?

Sperm whales produce one of the loudest known noises (180 decibels), loud enough to stun giant squids and communicate over long distances with other sperm whales. If one of their clicks was heard in the open air it would be louder than a 747 taking off and twice as loud as an elephant trumpeting.

By most measures, sperm whales are the loudest animals, but many believe blue whales are louder because of call duration. USA Today reports: The sperm whale is technically the loudest animal in the world, but the answer is up for debate because how we perceive loudness is subjective. [Source: Clare Mulroy, USA TODAY]

According to BBC, the sperm whale is perceived to be louder than the blue whale. A blue whale's call is 20 Hz and a sperm whale’s click is about 10,000 Hz. The sperm whale registers at 230 dB while the blue whale is at 188 dB. “For us to hear blue whale calls, they must be made at an intensity of 70 dB or more,” BBC writer Ella Davies reports. “But for sperm whale clicks, the human hearing threshold is around 15 dB.”

But the other factor is duration — a sperm whale’s click only lasts 100 microseconds while a blue whale call can last up to 30 seconds, BBC reports. Sound is also perceived differently underwater because water is denser than air. It travels faster and further in the water. So the sperm whale is technically louder, but if you perceive sound based on combined loudness and duration, the blue whale is a close contender. For comparison: the loudest human yell was 129 decibels. The loudest dog bark was 113 decibels. At 70 decibels, you may feel annoyed by the sound. At 140, you'll feel pain.

Sperm Whale Communication and Language?

Sperm whales appear to communicate through series of clicks that are differentiated by the number of clicks and the intervals between them. Different groups speak different “languages” and “dialects.” One researcher counted five different dialects among whales in the Pacific and one in the Caribbean. A sperm whale click recorded off of Norway was made up of a series of diminishing pulses that together last between 10 and 30 milliseconds. Scientists that recorded sequences of clicking made by pair of sperm whales had difficulty determining which whale was making what noise and called in a Senegalese master drummer to help them distinguish one whale’s sounds from the other.

Hal Whitehead at Dalhousie University has deciphered four distinct patterns of sperm whales calls and clicks. Eric Wagner wrote in Smithsonian magazine: The most common are used for long-range sonar. So-called “creaks” sound like a squeaky door and are used at close range when prey capture is imminent. “Slow clicks” are made only by large males, but no one knows precisely what they signify. (“Probably something to do with mating,” Whitehead guesses.) Finally, “codas” are distinct patterns of clicks most often heard when whales are socializing. [Source: Eric Wagner, Smithsonian magazine, December 2011]

Codas are of particular interest. Whitehead has found that different groups of sperm whales, called vocal clans, consistently use different sets; the repertoire of codas the clan uses is its dialect. Vocal clans can be huge — thousands of individuals spread out over thousands of miles of ocean. Clan members are not necessarily related. Rather, many smaller, durable matrilineal units make up clans, and different clans have their own specific ways of behaving.

A recent study in Animal Behaviour took the specialization of codas a step further. Not only do clans use different codas, the authors argued, but the codas differ slightly among individuals. They could be, in effect, unique identifiers: names. Whitehead, who was a co-author of the paper, cautions that a full understanding of codas is still a long way off. Even so, he believes the differences represent cultural variants among the clans. “Think of culture as information that is transmitted socially between groups,” he says. “You can make predictions about where it will arise: in complex societies, richly modulated, among individuals that form self-contained communities.” That sounds to him a lot like sperm whale society.

Sperm Whale Language and Social Behavior

Craig Welch wrote in National Geographic: Sperm whales use the world’s largest brains to operate nature’s largest sonar system. They send pressurized air through their snout, creating clicking sounds. They string these clicks together in rhythmic codas, rather like Morse code. Each coda lasts seconds or less. Some are three clicks; some may be a dozen or more. Over decades Whitehead recorded clicks by the thousands. [Source: Craig Welch, National Geographic, April 15, 2021]

He had no clue what the whales were saying, but one day in his lab in Nova Scotia, Whitehead created a chart summarizing recording data from all these whale groups. He spotted a trend: Roughly half made a common repertoire of calls. Their codas had similar patterns. Other units used different arrangements. “I was blown away.” These small whale units were part of something bigger — whale clans of hundreds or thousands. And each clan was speaking its own dialect.

Why would these animals, many of which had never met, have shared common calls? It’s a group moniker, it was theorized, a way to say, “I’m one of you.” They knew small groups spent time with others in their clan, but never with outsiders. And in the inky black of the sea, sound is how they’d see who was around.

Whitehead suspected click-codas were similar to human markers of cultural identity. Think, he says, of the gear worn by English Premier League soccer fans. “The Manchester United supporters parade around with a red scarf, the Manchester City with a blue scarf,” Whitehead tells me as dusk settles over the Caribbean. They don’t all know each other, and don’t mingle. Yet fans find their way to pubs to watch matches together. “It suggests this higher-level thing that’s really important to the whales,” Whitehead says.

Over time he and others also documented that whales in two distinct clans in the Galápagos had startlingly different habits. In one, whales cruised the sea in meandering formations, while in the other they swam in straighter lines. One clan stayed close to land, the other moved farther offshore. During El Niño periods, when waters warmed, whales in both clans struggled to get enough food, but one clan had a harder time than the other.

Gero also discovered that small units within clans appear to emit family-specific codas, almost like surnames, while individuals communicate in click patterns with subtle, signature variations, like first names. Using nothing but clicks, Gero can tell which whale in a unit is speaking about 80 percent of the time — “way better than random chance,” he says. Gero even recorded baby sperm whales making random clicks before winnowing their repertoire. They were zeroing in on their clan’s dialect, like infants babbling before saying “mama.” They were acquiring cultural norms before him in real time.

Image Source: Wikimedia Commons, NOAA

Text Sources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Wikipedia, National Geographic, Live Science, BBC, Smithsonian, New York Times, Washington Post, Los Angeles Times, The New Yorker, Reuters, Associated Press, Lonely Planet Guides and various books and other publications.

Last Updated May 2023