The southern resident killer whales that surface off Washington state and British Columbia carry distinctive repertoires of clicks, whistles and pulsed calls. Researchers who have listened to them for decades can often identify which pod is nearby from the shapes and sequences appearing on a spectrogram.
Three pods make up the southern resident community: J, K and L. They frequently travel through the same inland waters as Bigg’s killer whales, the mammal-hunting ecotype once commonly called transients. Yet the two communities live according to markedly different diets, social patterns and acoustic traditions.
That does not necessarily mean they hear literal gibberish when the other group calls. Scientists have not translated enough killer-whale communication to make that claim. What the recordings do reveal is something remarkable enough on its own: groups sharing the same coastline can maintain recognizably different vocal cultures across generations.
A discovery built from years of listening
Canadian biologist John Ford began systematically recording killer whales off British Columbia in the late 1970s. By comparing thousands of vocalizations, he showed that resident pods repeatedly used limited repertoires of discrete pulsed calls.
Ford described each repertoire as a dialect. The term did not mean that killer whales possess human-style language, but it captured the central finding: the calls were learned, group-specific and recognizable enough to distinguish one pod from another.
Some pods shared several call types, suggesting a history of social or cultural connection. Ford grouped these related repertoires into what he called acoustic clans. J, K and L belong to the same southern resident clan, while northern resident communities are divided among several other clans.
The repertoires are durable, but they are not perfectly frozen. Call types can remain recognizable for decades while accumulating small changes in timing, pitch and structure, much as pronunciations can shift while a spoken word remains understandable.
The same coastline, but different ways of life
Resident and Bigg’s killer whales are usually described as ecotypes: populations that occupy overlapping waters but have developed different ecological and social lives.
Residents eat fish, with southern residents relying heavily on Chinook salmon. They usually travel in stable family groups and can be highly vocal while moving or foraging.
Bigg’s killer whales hunt seals, sea lions, porpoises and other marine mammals. Because their prey can hear underwater, they often travel quietly during a hunt and become more vocal after a kill or during social activity.
Their ranges overlap, but they generally do not form mixed social groups. Their contrasting call repertoires are therefore part of a wider separation involving prey, hunting behavior, group size and family structure—not proof that one population possesses a language the other cannot comprehend.
How a calf acquires a family voice
NOAA Fisheries describes killer-whale pulsed calls as learned and culturally transmitted. The agency also describes them as signals that help maintain group cohesion and function as family badges.
A resident calf grows up surrounded by the calls of its mother, siblings, aunts and grandmother. Through repeated exposure and vocal practice, it comes to use the repertoire of its matriline and pod.
Researchers have documented early vocal development in calves, but the process should not be reduced to a universal timetable in which every animal masters its dialect by a particular birthday. Recordings from newborns are difficult to obtain, individuals develop at different rates, and much remains unknown about how imitation and vocal control emerge.
The important point is cultural rather than chronological. The calf is not born with a complete J-, K- or L-pod repertoire. It acquires its social voice from the whales around it.
The catalogue that made dialects traceable
Scientists can connect particular calls with particular families because killer whales in the region have been tracked individually since the 1970s.
Michael Bigg, the Canadian researcher whose name is now used for Bigg’s killer whales, helped pioneer photo-identification using the shape of each dorsal fin and the pale saddle patch behind it. Those features allow researchers to recognize individual whales from year to year.
Every southern resident receives an alphanumeric identifier tied to its pod. J2, widely known as Granny, was followed for decades before she disappeared in 2016. The same long-running catalogues document births, deaths, maternal relationships and movements.
When an identified family passes a hydrophone, researchers can compare the calls with older recordings from the same social line. That combination of genealogy, photography and sound makes the Pacific Northwest populations one of the best-documented examples of vocal culture outside humans.
What the calls actually sound like
Killer-whale vocalizations are generally divided into clicks, whistles and pulsed calls.
Rapid click trains are used for echolocation, allowing a whale to detect and track objects or prey through reflected sound. Whistles are continuous tonal signals often associated with social contact. Pulsed calls are structured bursts that contain many of the recognizable features used to classify pod dialects.
To a human listener, some calls resemble creaking hinges, squeals, trumpets or distant electronic alarms. On a spectrogram, however, researchers can see repeatable contours and frequency patterns that the unaided ear may miss.
A pod does not rely on a single identifying sound. Its dialect is a repertoire, and the pattern of which call types are used—and how they are produced—creates its acoustic signature.
Why acoustic identity matters
Sound is essential in coastal waters where visibility can fall to only a few meters. Calls help whales remain in contact while individuals spread out to travel, socialize or search for prey.
Dialect similarity can also reveal historical relationships. Closely associated resident pods may share several call types, while more distantly connected groups share fewer or none.
That does not establish a simple rule in which a whale listens to a prospective mate and calculates genetic distance from the voice. Killer-whale mating behavior is difficult to observe, and researchers have not demonstrated the kind of acoustic “sweet spot” that would turn dialect into a reliable partner-selection mechanism.
The better-supported interpretation is that calls mark social belonging. They help an animal identify familiar companions and preserve the distinctiveness of a community whose members may remain together for life.
Human noise is making those signals harder to hear
The Salish Sea is crossed by container ships, ferries, naval vessels, recreational boats and whale-watching traffic. Their combined sound creates a busy acoustic environment through which killer whales must communicate and echolocate.
Research across many animal species has found that anthropogenic noise can mask calls and alter vocal behavior. Animals may respond by calling more loudly, shifting frequency or changing the timing of their signals.
Southern residents have been observed increasing their call amplitude when vessels are nearby. NOAA Fisheries also reports that vessel noise and disturbance can reduce feeding opportunities and change how the whales travel.
Calling louder does not mean the dialect itself is disappearing, but it changes the conditions under which that culture must operate. A signal that evolved to cross open coastal water must now compete with engines, propellers and overlapping sonar.
A language, or something adjacent to it
Killer-whale dialects possess several features associated with language-like systems. They are learned rather than purely instinctive, transmitted socially, maintained by communities and capable of gradual cultural change.
What has not been demonstrated is human-style grammar or open-ended syntax—the ability to combine a limited set of units into an effectively unlimited number of new meanings. Researchers also cannot yet assign dependable translations to most individual calls.
New recording systems and artificial-intelligence tools may help. Efforts to use AI to examine animal communication can search enormous sound archives for patterns, sequences and behavioral associations that a person listening manually might overlook.
Those systems may reveal more complex structure in killer-whale calls. They may instead show that the signals are rich forms of social coordination without anything resembling sentences. Either result would deepen the picture without requiring scientists to force human language onto another species.
What remains when a family voice disappears
NOAA’s July 2025 census counted 74 southern resident killer whales. The population remains endangered, pressured by limited salmon availability, contaminants, vessel disturbance and the small number of animals left to reproduce.
When an individual dies, the community does not necessarily lose an entire call type. Other relatives may still use it. But the death of a matriarch can remove decades of ecological knowledge and a particular version of the family repertoire.
If a matriline disappears, some vocal variants may vanish with it. No recording can return that tradition to living whales once there is no calf left to learn it.
On a quiet evening around the San Juan Islands, a hydrophone can still capture a call type Ford catalogued decades ago. The whale producing it was not present for those first recording trips. She learned the sound from relatives who learned it from relatives before them, carrying a recognizable family voice through water that has changed almost beyond recognition.