Tahlequah, one of the last survivors of the endangered Southern Resident Orca population, is carrying her dead calf for the seventeenth straight day. She has traveled more than 1,000 miles with her dead baby, carrying her daughter along and refusing to allow her to rest on the ocean floor.
This group of orcas has not had a successful birth in three years. There are many possible explanations for this sad fact, and unfortunately, human activity is the likely culprit in each one of them. Our power boats make noise which disrupts their sensitive hearing, masking the echolocation and communication signals that they use to experience their undersea world. It would be analogous to humans losing our sense of sight—the sense that tells us the most about the world around us.
Our hydroelectric dams and overfishing have limited their only food supply – salmon. Each orca population has its own distinct culture that is passed down to younger members of the group by the elders. Many orcas have a culture of hunting and eating various types of food, but the culture of this particular group is to eat only salmon. Sadly, that means their food supply is now quite limited. Other whales in this group are starving.
So, what is going on with Tahlequah?
Like humans, orcas have complex brains. They also have a special brain region called the paralimbic lobe which appears to be highly developed (and perhaps more so than in human brains). This lobe features thick connections between the part of the brain that processes emotions and the part involved in cognition (thinking) and other higher-order capacities. Moreover, other parts of their brain involved in social awareness and communication are also highly elaborated. Orca behavior and their unique brain structure point to a possible “distributive sense of self,” meaning that the “I” in their mind is not separate from their pod. This idea might be behind the mass beaching seen in certain whale populations.
When a young calf dies, her mother may not only be feeling profound grief— she may be feeling as if a part of her has truly died as well. Perhaps that is why Tahlequah will not let go.
However, according to whale scientists, this prolonged mourning period is unusual. Could she be trying to communicate with humans? Could this intelligent creature be trying to show us her need for help?
Given that we know that orcas pass down their cultural traditions over generations, her pod must have a long collective memory. They are most likely aware of the boats and humans increasing as their food supply has been dwindling. Could Tahlequah be making that connection, and asking us to stop? It would certainly not be too far-fetched—wild cetaceans have tried to communicate with humans on other occasions, such as when a wild dolphin entangled in fishing line approached a scuba diver for help.
Sadly, Tahlequah is trying to make us aware of a simple fact: continued human-induced stress on this population might lead to their extinction. If this group disappears, an ancient culture that we have barely started to understand will be lost forever.
However, the more we know about their complex brains and the way they see the world, the more we can do to advocate for their protection. We know they use echolocation to “see” and to hunt underwater – let’s keep our oceans quiet so that they can hunt in peace. Let’s open the dams and give them back their food supply.
It’s time for humans to listen to Tahlequah’s silent cry and to lend her the voice that she does not have.
– Veronica Slootsky for OCR
Veronica Slootsky, MD is a practicing psychiatrist and divemaster with an interest in transcultural psychiatry and the treatment of post traumatic stress. She is working on a project with cetacean neuroscientists that aims to clarify whether captive cetaceans suffer from post traumatic stress disorder.
Thanks to Dr. Lori Marino for her input to this piece.