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The Tufts Daily
Where you read it first | Sunday, May 19, 2024

Do whales think about tomorrow?

Renowned marine mammal biologist, Dr. Hal Whitehead, has spent his career listening to the world’s largest creatures, and he joins me below for a conversation on what we might learn from the social lives of whales.

sperm_whale.jpeg

A mother and baby sperm whale.

Editor’s note: This interview has been edited for length and clarity.

Amelia Macapia: Let’s start with whale culture. This isn’t a figure of speech but rather an observation that whales communicate. Now, maybe everyone thinks all animals communicate, but you mean something very specific. What is that?

Hal Whitehead: A culture doesn't need communication, it needs learning. The essence of culture is social learning, one animal learning from another. That could involve communication, but it doesn't have to. You can just watch or listen to someone and learn something, and that changes your behavior. That’s culture.

AM: What are some examples of social learning in cetaceans (dolphins, whales, porpoises)?

HW: Probably the best example would be the songs of the humpback whale. The songs are long and elaborate, and the whales can sing for 24 hours continuously. The song is highly structured and made up of song cycles, [which are] made from themes, phrases, then notes, and they all have particular orders. It’s a very complicated signal and the song changes over time. All the whales in one ocean are singing the same song, and then gradually the songs change over time. There is no way that can happen if the whales are not listening to each other. So, they are aware of each other, and they are learning from each other. That is, of course, a type of communication. 

AM: With humpback whales, there is rapid cultural evolution, where a single song will travel eastward around the globe within a 2-3 month period. With sperm whales, you have clans, or societies, that differ vocally and behaviorally, and each has their own dialect. Are the different clans able to learn from each other like humpback whales or does social learning refer to learning within a clan?

HW: We don't know that actually. Mostly it is within a clan, but there may be occasions where there is social learning between clans. What we find is that two clans that spend time in the same area tend to have somewhat different dialects, more different than sperm whale clans which never or very rarely are in the same area. This means that the clans are listening to and learning from each other and then adapting their sounds to be different from each other. It is a slightly odd form of social learning, where you are getting information from the behavior of another animal and adapting your behavior to be different. There have been suggestions that, for instance, the signature whistles of bottlenose dolphins are like this. So, an individual listens to its mother and then makes a signature whistle, which is significantly different from its mother’s, so they are easily distinguished.

AM: I am also interested in the impacts of human-produced noise on the marine environment. Some researchers have suggested that there will be a point at which whales will no longer produce their calls anymore because they are being drowned out by the noise of industrial shipping and vessel traffic. Is that a threat to sperm whales?

HW: Noise is indirectly impacting sperm whales. Their populations are kind of always on the brink, and they cannot increase very quickly. They are not like codfish, which can produce a million eggs. The populations in areas where there is a lot more human impact, like the Gulf of Mexico, the Eastern Caribbean Islands or the Mediterranean, seem in worse shape. There are a number of human impacts happening in those places, but noise is certainly one of them. It is reasonable to suppose that the noise is a problem for them, and that it may be a big part of the overall problem [of their population decline].

AM: Has there been evidence of cultural learning for avoiding human-produced threats in the ocean? Is that something that can be taught to whales?

HW: There is some evidence, and this was a study we did on the behavior of the whales around whalers in the 1820s. Whalers of that era, who were the ‘Moby Dick-type whalers’ mainly from New England, kept pretty good records of what they saw. We have records of where they found whales, where they killed whales and so on. In around 1818, whalers moved into the North Pacific and sperm whales were in that area. ​​The rate at which they killed sperm whales that they had already sighted declined quite dramatically by 60% over the first five years of whaling. It looks like the whales learned really quite quickly, and almost certainly from each other, good ways of avoiding being killed by whalers. So, that is a cultural adaptation to minimize the effects of a human threat which seemed to be pretty successful for the whales. They were still being killed, but not at the same rates as they had been initially.

AM: We have been talking a lot about social learning, but going back to the word culture, why is it important to use that word? Is it controversial for a biologist to use the word culture?

HW: It’s definitely controversial and there are different perspectives. In the whale field, it has become considerably less controversial over the last 20 years, and I think in the primate field it has too. Whale scientists are principally biologists. For biologists, the idea of introducing culture as something determining behavior or phenotype was a bit of a step. If you go back 30 or 40 years, the perspective was that genes were the only important thing. But then biologists realized epigenetics can be important, and that culture can be important.

The primatologists have had a harder time for a number of reasons, and one of them is that many primatologists are anthropologists. And some, but certainly not all, anthropologists see themselves as the guardians of the word culture. As one put it to me: “Having biologists tell me what culture is, is like me telling biologists what genes are.” And so there is certainly resistance to it. Some think that we biologists just went ahead and defined culture as we thought fit without reference to anthropology — the study of culture — and some are aggrieved because they think culture is specifically human. These different threads lead to different levels of unease with biologists talking about culture.

AM: What patterns and parallels are there between cetacean culture and human cultures?

HW: There are foraging cultures in both. Bottlenose dolphins in Florida feed on fish balls in shallow water by making a mud ring. Similarly, hunter-gatherers have ways of hunting and gathering which are their culture. Modern farming is also a culture. Then there are social cultures. For instance, the way two Americans will greet each other is different from the way two Indians from India will greet each other. Similarly, the way some orcas from the southern resident community greet each other is different from the way northern resident orcas will greet each other; these are social attributes. Then, there are clearly vocal cultures. We talked about the humpback songs. Humans have songs, too, and other kinds of music as well, which we learn from each other. Those are all parallels at different levels, but there are also big differences, one of the most obvious being technology.  

Cetaceans have only the most simple forms of material technology. Bottlenose dolphins put sponges on their noses to protect from sharp objects while foraging on the seafloor. That is about as far as it gets, while humans have space shuttles and iPhones and whatnot. One aspect of human culture that has been seen as unique is symbolically marking our group identity. We wave a flag or speak with a particular dialect to show we are from a particular social group. Different groups put on especially intense forms of dialect. The symbolic marking of group identity was seen as likely unique to humans. However, the evidence, especially from sperm whales and killer whales, suggests that it is not unique to us.

Another particularly interesting comparison concerns the large-scale cultures of sperm whales and humans. We have ethno-linguistic groups, thousands or even millions of humans who feel they are part of the same group (e.g. Portuguese). It looks like sperm whale clans operate in a somewhat similar way. They're large in space and numbers, but one interesting and important difference is language. Language is culture because we learn our language from others. And humans who are brought up without other humans don't learn a language or produce a language. Language is learned, and, in that way, it is no different from the songs of the whales. But, it is syntactic and a semantic language, so that by putting the sounds we use in particular orders, we can produce an infinite number of meanings. There is very little evidence of semantic language in the wild for non-humans. Animals who spend a lot of time with humans seem to be able to learn and use semantic languages. Parrots, bonobos and dolphins learn a vocabulary in which different orders of the symbols mean different things, and so they seem to have the ability to do it, but they interestingly don’t seem to do it in the wild.

AM: Often language can be seen as giving orders, but you can also create a new horizon. For instance, what will tomorrow be like? If animals can do that, it means that we share something amazing — and maybe more than just communication. Do you think that's something we share with sperm whales?

HW: We use sounds to bond socially. This is important for us because we are cooperative creatures. Let’s say you walk out of your apartment in the morning, meet your neighbor and you say, “Nice day, isn't it?” It is not really information, but by saying that, you are building or reinforcing your relationship with them, which may or may not mean much but could become important.

We use language in many different ways. We sing lullabies to our kids, who probably don't care too much what the words actually say, but they like the tune. We sing martial songs as we march to war. Once again, the words may be important, but it is the tune and rhythm that gets us feeling warlike. Similarly, language and music are used in courtship. In that sense, our communication has parallels in other animals, across courtship, dealing with infants, expressing solidarity when a threat is posed and general bonding in a society where individuals depend on each other. You will see a lot of that in sperm whales, chimpanzees and so on.

When I heard sperm whale codas, I used to think that they sounded like Morse code. I presupposed that the sperm whale codas were used to convey information also in a noisy channel. But because of more evidence we have, some of my colleagues and I think that not all sperm whale codas are more about bonding and social relationships and less about conveying particular bits of information.

AM: What are the risks of particular clans dying out and losing their cultures in such a rapidly changing marine environment?

HW: There are risks to that, [and] we see it more clearly in killer whales, especially from studies

off the northwest coasts of Canada and the U.S. You see different social entities with very particular ways of life that are imperiled by what we are doing. Examples would be the southern resident community, which is around northern Washington state and southern British Columbia. That population is very small, with 70 or so animals, and not doing well. They continue to live in a highly used area by humans. There is a lot of noise from whale watching and a lot of pollution from shipping, and these things are getting worse. They specialize in a kind of food, the Chinook salmon, which isn't doing well. So it doesn’t look good for them. Further north in Glacier Bay, southeast Alaska, there is the AT1 pod, and they have very specialized ways of doing things. But they were in the area where the Exxon Valdez went down in the 80s. A number of the whales died then, and since then, they have had no calves, and they are on their way out. There are other groups of killer whales, which for one reason or another, are less vulnerable to us. All these things will affect the different groups differently, and we might expect the same for sperm whales, but it’s harder to tell.