Dialects Of The Whales

Correspondent Vicki Mabrey interviewed John Ford, head of the Vancouver Aquarium's marine mammal research, last summer. Here are excerpts from that interview:

John Ford: Boy, that goes back to when I was a young lad growing up on Vancouver Island. I'd go out fishing with my dad, … and these whales would go by. And of course we were all terrified because in those days everybody thought that they were vermin and incredibly dangerous predators of people.

Later I actually became interested in them here at the Vancouver Aquarium where I got a job sweeping popcorn up after the whale shows. And I … spent a lot of time leaning on my broom and watching.

Mabrey: They talk to each other. How do they use these sounds?

Ford: They're very sophisticated acoustical animals. In fact, their evolution — the whole head structure of killer whales and other dolphins has been modified to be incredibly for producing sound in water beneath their blow-hole, and it's beamed forward through the fleshy melon on the front of their head. And they receive sounds through their lower jaw.

And a lot of this adaptation seems to be for echo location. They make clicking sounds that they use to navigate and to find food. They (e)mit these series of clicks that produce very faint echoes that they can interpret to form three-dimensional acoustical images.

What has lagged behind, especially in terms of field studies, is what they're using their social signals for, the kind of cries, screams, whistles.

Mabrey: Do all killer whales talk to each other?

Ford: Yes, they do. They especially like to talk within their own kind, and that's where this starts to get very complex.

Because, killer whales are creatures of tradition. They grow up in their group, they learn from their mother, grandmother. They live in these matrilineal societies. And they learn how to hunt in their particular way.

Some whales on the coast of British Columbia here focus on feeding … on salmon and other fish. A whole other type of killer whales that lives in the same waters, but never mixes and they don't talk to the fish eaters, are called transients. And they actually eat only mammals, porpoises, seals, things with warm blood. They don't touch fish.

And so these are examples of different cultures of the same type of animals that coexist, but they maintain complete separation socially.

Mabrey: So are their sounds different?

Ford: Their sounds are very different. In fact, that's what's unique about killer whales is that family groups actually learn and develop a particular dialect that's unique to the group.

Mabrey: So, whales are in pods, and … these are family groups?

Ford: That's right … They actually have a unique social systein that when a whale is born to a group, a female in a group, it stays in that group for life. And this is very, very unusual, if not unique among all mammals. There's no dispers(ion), what it's called; there's no emigration from the group into which a whale's born. They just don't transfer from one group to another. They stay in that matriline.

And so the pods of what we call resident killer whales, the salmon hunters, the ones we know best, actually can consist of three or four generations of matrilineally related whales.

And what seems to have happened in these matrilines that may persist for many, many generations — centuries perhaps — is they develop their own peculiar dialect and pass it on from generation to generation.

Mabrey: What do you mean by a dialect?

Ford: They have, on average, about a dozen very stereotyped, distinctive calls that they use, … about a dozen for each pod. And those calls sometimes are shared among different pods, but sometimes a pod will have a unique one.

Some pods in the same area will have none in common. And so what we actually have is a pattern, a very complicated pattern of acoustic similarity and difference that tells us about the history, the evolution of the population on the coast here.

By comparing different dialects we can say, "Well, these pods probably split perhaps a few generations ago from a single, larger group." Maybe female cousins gradually … drifted apart. … In doing so, their dialects gradually, slowly changed, probably through copying errors across generations.

And then even within the same population, we have collections of pods that are completely unrelated in their dialect. And these we call different clans.

Mabrey: Pods and clans, and generations.

Ford: Very likely it's a matrifolkal society, meaning that they're — the oldest granny in the group is the boss, she's the matriarch. And much of what they do may be determined by the matriarch. And when we see different pods traveling together, often these old grannies swim side by side because they might be 70, 80 years old.

Mabrey: They have the life span of human beings?

Ford: They can live that long. On average females live about 50, but we don't know how long they can live.

And so we now know that these killer whales … have a highly structured kind of family society. The big question has been, who's Dad? If you're living with your mum and your grandmother and you're a male, you're not breeding in that group, hopefully, because that wouldn't be a good idea.

It turns out that they seem to be breeding across pods. So males will … mate with a female in a different group and then come back to the group.

We can't say that they have a language like ours; there's no evidence for that yet.

Mabrey: No nouns, verbs.

Ford: Not that I've ever een.

Mabrey: Now, are they using the sounds to mate as well, to find partners in these other sounds? … If their dialects are different, how do they understand?

Ford: That's a great question, one that we've been sort of scratching our head about for many years. And the new genetic studies that are coming out … are suggesting that maybe it is true what I thought years ago.

OK, if you're living in your family group for life and … you don't want to mate with your close kin, so how are you going to know who to mate with? Well, maybe they can tell how … distantly related potential mating partners are from their dialect, just as we can tell how distantly related they seem to be.

This is probably the case, that they're actually selecting mates outside their family group. And the dialect might be a reliable means of preventing inbreeding in that way.

Mabrey: So they would look then for sounds that were unfamiliar?

Ford: That's right, (or) they'd be attracted by foreign accents, if you like, something exotic.

Mabrey: Are they all making … the squeaks, the squawks, the squeals; … they're all doing that? It's the same set of sounds, but … it's the way they're using the sound differently, putting them together?

Ford: That's right, … it's actually not quite that they're using all the same set. Some pods, for some reason, only make five or six different calls. Other pods might make 15 or 16.

On average it's about a dozen. It's part of kind of the mantra of the group. Some groups have lots of different sounds; some stick to only a few. Don't know why.

And some of them are based on a very similar format; you know, they're all sweeping up in pitch. But there are usually features that are quite distinctive between these groups. There's a real almost limitless array of possible sounds that they can make.
Mammals just don't generally have these kinds of dialects, and that's probably because most mammals are pathetic … at learning new sounds. They're just not capable of it because their sounds are determined genetically.

Mabrey: How good is their hearing?

Ford: Exquisite. We can't really imagine it because we only hear up to around 16,000 hertz in frequency. That's as high as we can go.

Killer whales and other dolphins can get over 100,000 hertz in frequency. So, much of the sounds that they make, especially for their echo-location, … their clicking sounds that they use for orientation and finding prey, those are above our hearing.

Fortunately for us they choose to make a lot of sounds in our hearing range, but they certainly make sounds and can hear far higher than that.

Mabrey: Do you think they have real musical understanding?

Ford: They're very curious about musical sounds, very curious.

I've certainly … seen them at the auarium here and out in the wild being very curious, approaching boats that are playing music.

They're inquisitive, and being so focused on sound, it's a new acoustic feature in their environment.

But whether they have a sense of rhythm as we do, or … some higher aesthetic interpretation of it, I just don't know.

Mabrey: So, if a choir, … as it did in June, went and sang to them, are they really coming because they see people standing on the shore looking at them? Or are they really hearing this … and they're curious?

Ford: They're hearing it. Their hearing is great. You know, sound in air doesn't transmit into water very well. And so unless it's produced in the water they probably can't hear it very far away.

But, again, I think that … they would be attracted for a while, and … be curious. But they probably, after a while, would get kind of anxious to go after, go off and chase salmon again.

Mabrey: How do the whale sounds affect you personally? I know you're studying it as a scientist.

Ford: There's no question that at times I put the analyzer away. And these times are often when I'm in my boat up the coast anchored at night, and lying with the hydrophone cable over the … side of the boat, and … the speaker just going. And then hearing the whales in the distance with their … sort of magical sounds echoing down these 1,500-foot deep canyons of the inside passages - it's just an amazing experience.

And knowing that … these sounds are traditions that have been passed on for generations, maybe hundreds of years, maybe longer.

They're also just intrinsically beautiful to listen to as they echo off these canyon walls. And you know, they're … very special sounds.