Two weeks ago, I saw ‘Blackfish’, the fascinating new documentary about killer whales in captivity. Here’s the trailer.
I enjoyed the movie, but it left me with questions. A lot of questions. Neuroscience questions. What makes whales different from other animals? How do whales perceive humans? What did the filmmakers mean when they said that killer whales have a wide range of emotions? How smart are these animals, really?
Read the interview in French here.
So I called up Lori Marino, a neuroscientist prominently featured in ‘Blackfish’, and asked her to satiate my curiosity.
In this interview, Marino and I switch around between referring to whales, killer whales, orcas, and cetaceans. For the record, cetaceans = an order of marine mammals. Whales are cetaceans. So are as dolphins and porpoises. Killer whales (a.k.a. orcas or blackfish) are a type of cetacean.
You’re currently a professor of cetacean neuroscience at Emory University and have worked in the field for over 20 years. What drew you to study this subject?
In grad school, everyone was studying primates. I wanted to study another animal — a group of species that were comparably intelligent, but we knew relatively little about. I started to look up dolphins and whales. When I saw a picture of the brain of a dolphin in a book, I was hooked. I thought, “Wow. This is really something.” And we knew very little about the brain of a dolphin or a whale 25 years ago, so I saw this as an opportunity.
It seems like it would be more difficult to study a whale brain than, say, the brain of a rat or a monkey. Are there special challenges to studying the brain of an animal that’s so large?
Yeah, it is more difficult, because the brain itself is so different from any other mammal brain. That’s part of what hooked me: the idea that this a very big brain. It was just put together differently than other mammal brain.
Magnetic resonance imaging, or MRI, is a device that allows scientists to look inside the body. MRI uses radio waves to create a 3D picture of a given area.
The other difficulty is, because it’s so large, it’s not easy to use the same techniques that you use with small brains. It’s much bigger than even the largest non-human primate brain. The dolphin brain is even bigger than the human brain. It’s very difficult to study. But once we were able to use techniques like magnetic resonance imaging, that’s when things really took off, because we could take the brain, put it in a scanner, get the digital images in 3D, and do what we could normally do dissecting any other brain. … MRI really opened up the field.
“It’s like they’re
What are some characteristics that set killer whale brains apart from human brains? In ‘Blackfish’, you and the other scientists mention that a particular area of the orca brain is enlarged.
If you look at the limbic system — the emotion-processing area in all mammal brains — you find something really interesting. There’s some parts of the limbic system of dolphins and whales that have changed and actually gotten smaller, but there are other parts of it that are adjacent areas that are much larger and more elaborate than in the human brain. That area is called the paralimbic region.
So they have like an extra lobe of tissue that sort of sits adjacent to their limbic system and their neocortex. And, you know, you can infer from that. That lobe has something to do with processing emotions, but also something to do with thinking. It’s very highly elaborated in most cetaceans and not at all or not nearly as much in humans or other mammals, so it suggests that there’s something that evolved or adapted in that brain over time that did not occur in other mammals, including humans.
In the movie, this is said to be a sign of a range of emotions that possibly outranks that of humans.
Yeah, I think that it’s hard to say it outranks. …
If you look at, say, the brain of an orca [and] the brain of a human, it would be difficult to say that the human brain was capable of more emotional depth than the orca brain, because — again — what you see in the orca brain is an elaboration on the limbic area that the human brain doesn’t have.
So if that part of the orca brain is doing what it should be doing, as it does in all mammals — that is, processing emotions — it suggests [that] these animals are doing something very sophisticated or complex while they’re processing emotions. And I think also when you look at behavior of dolphins and whales, especially in the wild, you see a level of social cohesion that is really unmatched in other mammals including the humans.
Yeah, I wanted to ask you about that. ‘Blackfish’ also indicates that killer whales may have a distributed sense of self.
That’s a really interesting idea that’s been around for a while, and it’s gonna be very difficult to test.
The idea is that when you look at how they communicate with each other, how they move amongst each other, and what their social lives are like, it suggests that there is something about being an orca or a dolphin — or any other one of these cetaceans that are highly social — that might actually be something a little bit different than what it would be like to be just an individual. And the reason we say that is how they communicate amongst themselves when they’re traveling and how they respond when one individual is detained or injured or harmed or attacked. It’s really interesting. There’s been a lot of discussion about why do they have these mass strandings and how is it you that get to capture all these animals all at once. In Taiji, Japan, when they slaughtered them, why [didn't] they just jump the nets? …
In a mass stranding, a group of cetaceans will leave the water, cast themselves onto the beach, and — usually — die. A stranding might involve hundreds of animals at a time, all alive, often healthy but distressed. Scientists are not sure what causes mass strandings to occur.
It suggests there may be something about their sense of self that is not only an individual, but depends very much on their social group. It’s not part of their psychology possibly to sort of disconnect from their social group in the way, say, humans might be able to if we had to. So it’s certainly just, you know, at this point a suggestion. But [it] seems to be descriptive of some of the ways they seem to act that we really can’t explain. When one animal is sick and heads to the shore, why does the whole group do that? Or in the case of [some male orcas], if the mom dies they may die as well. They stop eating and go into some sort of a clinical depression and die. Not all of them but some have. We’ve observed this. What is that? What is that sort of social cohesion they have?
Are there any other mammals suspected to live in this kind of social group?
Ungulates are hoofed animals. For example, horses, deer, camels, rhinos, pigs, hippos, and giraffes are all ungulates.
You know, it’s so interesting, because you have to think of where cetaceans came from. They’re ungulates, or they were ungulates. Their closest relatives are the hoofed animals or other herding animals. So, when you look at the cetaceans, [herding] is in there. But they seem to have taken it to another level.
If you look at herd animals… it’s not clear there’s the sense of self like there are in dolphins or whales. Dolphins and whales will stand by each other. They won’t leave when there’s a chance to escape. And their behavior is tied more closely to the group than other ungulates or other herd-like animals. Somehow [herding behavior] got ratcheted up, we think, but exactly how that happened or why that happened we don’t understand. It’s like they’re super herds.
Maybe this isn’t the right way to phrase this question, but: How “smart” is a killer whale?
Encephalization is a technique used to describe the brain. Scientists score animals with an encephalization quotient by measuring the size of their brains and then comparing that to the size of their bodies. A high encephalization quotient means that an animal’s brain is larger than its body size would predict. Humans have the highest encephalization quotient of any species. Some scientists think that encephalization can be used to estimate an animal’s intelligence.
That’s a difficult but important and good question. You know, for the longest time I tried to figure that out by ranking their encephalization levels compared to other animals, particularly humans and great apes. If you use that as an inferential scale — or if you use that just to sort of get an idea of how much brain there is per body — you know humans are still the highest. Closely behind are many dolphins and whales, and then great apes, elephants, and a number of animals.
So if you look at it from a brain size perspective, or looking at how well elaborated the brain is, then they certainly seem to be right up there.
But if you look at their behavior that becomes more of a ground truthing thing. … [In previous studies] they showed capacities in understanding symbolic language, in memory, in problem-solving, in visual perspective. Diana Reise and I showed that bottlenose dolphins recognize themselves in mirrors. They show all of these capacities that are pretty rare in the animal kingdom.
And again, when you look at the field work, you see it’s supported by their cultures, their toolmaking, the sophistication of their social networks. All of the lines of evidence converge on the idea that they are these are very intelligent animals.
I’m sorry — did you say toolmaking?
Yeah! Oh, they make tools! There’s all different kinds of things they do.
Bottlenose dolphins, for instance. There’s a population off the coast of Australia, and what they do is they use tools. (I wouldn’t say this is toolmaking. It’s tool use.) They actually use sponges. They get the sponges from the bottom and they put them on their rostrum and they use them to root around in the sand for fish. It prevents their rostrum from being scratched up. And we know this is a culturally transmitted toolmaking behavior because we know exactly which individuals started it and how it got passed from her to her daughter and then both laterally and vertically. So [we] now have a group of sponge-carrying, sponge-using bottlenose dolphins that have carried on that tradition, as it were. …
Humpback whales also use “bubble nets” to catch their prey.
It’s not genetic. It’s not something that’s inherent and it’s not something that all individuals of a group will do. It seems to be passed on and carried amongst certain individuals, particularly females. Adult females tend to be the innovators, like it is among the primates. …
And we know now — this is really interesting — that sponge-carrying dolphins tend to hang out more with other sponge-carrying dolphins. It’s called the Sponge Club. It’s sort of the beginning of social segregation based upon the transmission of this behavior that somebody made up, this one female.
“They showed capacities in understanding symbolic language, in memory, in problem-solving, in visual perspective… all of these capacities that are pretty rare in the animal kingdom.”
‘Blackfish’ also showcases the close connection that trainers have with the whales they work with. How do whales like those seen in the movie perceive humans?
You know, that’s something that clearly the trainers have a lot to say about. I’ve worked with captive animals and it’s always a question in anyone’s mind how these animals actually perceive us. I don’t think anyone knows. There are some people that think there is very real intimate relationship, between say the dolphins or the whales and the trainers. But others will say that’s a contingent relationship. I mean, you’re the one that’s a purveyor of reward and punishment and there’s a lot of obvious inequity in the relationship, so who, you know, nobody knows.
I think these tragic incidents tell us that these relationships may not be what you think it is. In the movie, [one of the trainers] was saying, “You know, I want to think it’s more than just I feed them.” I don’t think anybody really knows. …
When you think about the psychology of the trainer and the captive, it’s not a healthy relationship, clearly. Because there’s somebody that has complete control and someone who doesn’t. So the extent that a captive can have, you know, a close relationship with a captor — I’m not sure that can be a healthy relationship in a real sense.
‘Blackfish’ makes the case that Seaworld’s killer whale exhibits are inhumane and psychologically damaging to the whales. What do you think should happen to the killer whales currently in captivity?
I think it depends on the individual. There are a lot of individuals that might be good candidates for rehabilitation and release. There are others that are not. The main thing is right now we don’t have any sanctuaries for dolphins and whales the way we have for elephants and chimpanzees and other animals. So there’s nowhere for them to go except back into the ocean, unless we have some way of keeping them in a [place] that is closer to their natural life, but still, you know, not doing tricks and not in a small pool.
That’s something that’s really important to develop: sanctuaries for them so that they have options.
But some of them I think are releasable with rehabilitation. We just had a bunch of bottlenose dolphins released from rehabilitation and released from a Korean aquarium. They’re now back with their families. It just depends how long they were in captivity, whether they were born there, all of that stuff. Once you takes an animal like an orca and remove them from their mother, their natal group, when they’re like two years old, you’ve done damage. It’s just a question of how that psychological damage will express itself.
Anything else that we should know about the movie?
I wanted to mention to you something about that scene where they show the orca in the MRI. That actually was not accurate. We never put a whole orca in an MRI. It would never fit. I think they did that to show the public, to help them understand. What happened was that the brain was taken out of the skull, and then the brain was put the MRI, so it wasn’t the whole animal. It’s just a technical thing.
If you want to learn more, check out this live Q+A Dr. Marino did after a showing of ‘Blackfish’ at her university.
Aviva Hope Rutkin is a science and technology reporter in the Boston area. She currently writes for the MIT Technology Review. She’s performing at StoryCollider in Cambridge, MA on August 27. Follow her @realavivahr.