Dolphins and whales are highly intelligent beings. Lori Marino believes they don’t belong in tanks at entertainment parks.
“We … feel that our brains are so large for our body and that’s why we are so, ahem, smart,” Marino said. “Yeah, OK, we have a brain seven times what you’d expect. Yeah, we’re brainy … [but] primates aren’t the only brainy guys on the block.”
Marino, who has a doctorate in biopsychology from the State University of New York at Albany, is the president and founder of The Whale Sanctuary Project, a group of activists and scientists attempting to build the world’s first nearshore safehaven for marine mammals that have been in captivity. She spoke to an audience of approximately 100 people at The Whale Museum on July 25 about orca intellect.
Scientists have traced orca ancestry back to a land mammal called Pakicetus that lived near the Tethys Sea 50-55 million years ago, Marino explained. The Pakicetus was a hoofed animal with a relatively small brain.
“That doesn’t mean he was especially dense,” Marino joked. “[Its brain was] small in relation to what it would become.”
According to Marino, approximately 45 million years ago the general whale shape began to appear in the form of the Ambulocetus, or walking whale.
“These early forms were called Archaeocetes,” Marino said, describing the Dorudon that was fully aquatic and lived 35-40 million years ago. “Then something happened. Isn’t that scientific?”
What happened, Marino explained, was nearly all the dolphin and whale species died from 20-35 million years ago, in the early modern cretaceous period.
“That shift is what made the difference in dolphins and whales,” she added.
Today there is “tremendous diversity” in cetaceans. There are two suborders of cetaceans: Odontoceti, or toothed whales, and Mysticeti, or baleen whales. Orcas belong to the former, and are actually a dolphin — or a member of the Delphinidae superfamily — not a whale, Marino explained.
“The evolutions of dolphins and whales is one of the spectacular evolutionary tales,” Marino said. “Not only did they change their way of life completely [but] their brains completely changed. … That shift changed their social ecology to one that started them on the road to being the complex social beings that they are today.”
Marino said scientists know this because she and her colleagues spent a lot of time at the Smithsonian Institute taking whale fossils and mapping their cranial cavities using a computerized tomography machine. With that information, she added, scientists could establish the shape and size of the animal’s brain and determine that 35 million years ago a shift occurred. Orca ancestors had sharp teeth and small brains but developed larger brains and smaller teeth, setting them on the path toward modern dolphins and whales.
The brains not only grew in size but also in complexity, Marino explained. The cerebrum of cetaceans are very large, she said, so they are “literally becoming more cerebral.”
Orca brains are 15 pounds and about the size of a very large basketball, according to Marino. Delphinidae brains are larger than what they’re expected to be for their size, and their body-to-brain ratio is larger than humans’ closest relatives.
The encephalization quotient is a scale of brain-to-body mass ratio. Humans have brains seven times larger than expected, she added, and orca brains are 2.5 times larger than they “should be” for an animal their size, meaning they have one of the largest brain-to-body ratios. To determine how this relates, hundreds of modern dolphin brains were measured, Marino explained.
Because of the size of dolphin cerebrums, there’s a lot of gray matter, which allows for abstract thinking, Marino said.
“There’s more gray matter per total volume in an orca brain that a human brain,” she explained.
According to Marino, about five years ago, scientists using diffusion tensor imaging, which is a type of magnetic resonance imaging, discovered that cetaceans have dual auditory tracks to their brains from their ears. Conversely, humans only have one. While one track processes echolocation, the second processes other sounds, and, according to Marino, the two communicate.
“We knew that dolphin whales were fancy in terms of acoustics,” she said. “We had no idea that we were talking about this fancy.”
Creases in the brain, Marino explained, indicate enhanced neurological function, because it adds area to the brain. If there is a crease in the brain, she added, it is there for a reason.
Within the brain is the cingulate sulcus, controls the being’s awareness and social cognition and more. Both humans and orcas have this crease, though the orca’s is more complex, leading scientists to believe it is more advanced, Marino said.
Then there’s the paralimbic lobe, which connects the emotional systems to abstract thinking.
“It is unique to cetaceans,” Marino explained. “We don’t have it.”
Scientists know that humans don’t have this lobe because all mammals have the same functions in the same locations of the brains, added Marino. This lobe connects emotions to problem-solving in cetaceans.
“It is just what I call a riot of tissue,” Marino said. “By understanding something about the brain. … it gives you insights.”
Such insights, Marino explained, are that these highly intelligent animals psyches are likely being affected due to the animals’ containment within too small concrete tanks in entertainment facilities around the globe. The captive animals that demonstrate hyperaggression, boredom, abnormal behavior, self-harm and systemic illness are simply in distress, Marino stated.
“We know that the brain shows distress in those concrete tanks,” Marino said. “That brain is a wild brain, it’s a complex brain. It doesn’t belong in entertainment.”
Marino’s proposed solution to the distress caused by concrete tanks is the creation of seaside sanctuaries wherein the animals can be exposed to their more natural habitats while not being left to their own devices in the wild.
“It’s still captivity, but their brain gets more of what it needs to survive,” Marino said.
“I don’t know if captive whales could be reintegrated [into the wild],” Marino said in response to whether she believes the animals should just be released. “It would be very, very difficult, if not impossible.”
For more information about The Whale Sanctuary Project, visit https://whalesanctuaryproject.org.