The Awesome Intelligence of Cetaceans (Part 1)
Why They Deserve Our Respect
Of all the wondrous beings we share this earth with, whales and dolphins, also known as cetaceans, are closest to us in intelligence. It is often difficult for human beings to understand just how intelligent these creatures actually are. This is because whales and dolphins exist in a world completely alien to our own. As a result they have evolved in ways that do not allow them to do some of the things we are capable of, instead focusing on other aspects such as streamlining the body, echolocation, visual, auditory and respiratory system changes and the process of switching from legs to fins. The brain, however, developed a great deal in both species. It is true that we are more advanced but we must consider the advantages we have had over them due to our environment and lifestyle.
As an introduction into the impressive intelligence of these creatures, I think it is important to explore the different environments our ancestors(ancestors of humans and of whales) faced and how this led to two clever but completely different beings. Early cetacean ancestors appeared as early as 54 to 33 million years ago! Early humans did not appear until about 5 or 6 million years ago. Apes evolved to climb in trees and pick nuts and berries which allowed us to have hands and feet that are ideal for grasping objects. The ancestors of whales and dolphins decided to return to the sea. They had no use for spindly arms and legs that would only slow them down. Their food source was quick and agile and they had to adapt accordingly. The fastest cetacean ancestors had the least amount of drag when they swam and therefore found the most food and were able to be more successful in passing on their genes. They unknowingly chose not to evolve with hands and as a result, could never have the ability to manipulate objects to create tools or build structures as easily as we humans can.
Another aspect to consider is the fact that cetaceans are surrounded by water which acts very differently than air. As it enters the water, light travels much slower than it does in the air and refracts or bends. This, combined with swimming at great depths where no light can penetrate or, in some cases, hunting in an environment that is murky with low visibility, has led to the evolution of whales focusing on the hearing sense rather than sight. This is not to say that they can't see, they have undergone several changes to their eye to allow them to see in both the air and the water and may even be capable of some color vision, however this sense tends not to be as useful as hearing in most cetacean species. I will go into more detail about this in another hub. They have a form of ear that is quite different from ours. Unlike our ear canal which is full of air, the canal of a cetacean is blocked by a plug of dense wax. Sounds are instead channeled to the middle ear through a fatty area around the lower jaw.
The ear of a cetacean is so different from those we are used to that much is still unknown about how it actually works but what we do know is that their inner ear at least, works like ours. From this discovery we have also learned that toothed whales(Dolphins, Killer Whales, Sperm Whales, Porpoises) possess an exceptionally high hearing range while baleen whales(Blue Whales, Fin Whales, Humpback Whales, Right Whales etc.) possess an extremely low frequency hearing range. To summarize my point, cetaceans have undergone these extreme changes to benefit the most from the one sense that works exceptionally well in an aquatic setting: hearing.
Humans are visual creatures, we have keen eyesight and are perhaps not as gifted in the auditory department. As a result, when we attempt to quantify the intelligence of a species, we use primarily visual tests. This works great for many land animals but whales and dolphins are at a disadvantage. They are also extremely large and seemingly slow moving in some species, which for some reason has made many assume they are slow mentally as well. Although many scientists and trainers alike have noted the exceptional intelligence of these creatures, many people from countries such as Japan, Norway and Iceland insist they are no more worthy or our respect than any cow or pig. This couldn't be farther from the truth. That is what I intend to prove with this compilation of information I have learned about these species.
Cetaceans possess the largest brains in the world but of course it is more than just size that makes an intelligent creature. Although we now know that high brain ratios alone do not always correlate accurately with intelligence, I think it is worth noting that the brain to body mass ratio of dolphins is second only to ourselves. Another interesting way to try to gauge intelligence is to compare a species brain size at birth with its size as a completely developed adult. This is supposed to indicate how much learning a young animal of this species can accumulate. Humans are born with only 28% of their adult brain size. Most mammals are born with almost 90%. Chimpanzees usually have around 54% while the bottlenose dolphin infant has only 42.5% of its adult brain mass.
Another amazing discovery was that of spindle cells in the brains of several species of cetaceans including: the humpback whale, the fin whale, the sperm whale, the killer whale, bottlenose dolphins, Risso's dolphins and the beluga whale. This is extraordinary because spindle neurons, discovered by Constantin von Economo, are a unique type of cell that is found only in the most intelligent of species including ourselves, the great apes and elephants. Although we do not have enough information about what impact these cells have on our brains, we can certainly make an assumption that it relates to intelligence because it is well documented that these species are highly intelligent.
We have tried for many years to devise tests that could accurately show how intelligent cetaceans, mainly dolphins, really are. This has been quite a challenge for us. One reason for this is the fact that most of these tests require a captive dolphin. This means researchers will be dealing with a stressed animal that does not want to be where it is and has often been separated from its social group. This undoubtedly has an impact on its behavior. Keeping that in mind let's look at some examples of these tests or what information was gathered from them.
The Dolphin Institute of Honolulu, has shown that:
- Dolphins are extremely talented mimics. Not only can they mimic the behaviors of other dolphins, they are able to understand that when a human lifts his leg, that corresponds to the dolphins tail which he then lifts up.
- Dolphins are able to interpret behaviors it sees on a television screen and respond accordingly. This is significant because dolphins are the first animal to respond to televised gestures.
- Dolphins are capable of recognizing themselves in a mirror and will inspect their bodies if they are provided with a reflective surface, much like humans. I have provided video footage below of this for your enjoyment.
- Dolphins are capable of understanding the command “do something different”. This means that a trainer can use this command and the dolphin will choose a trick to perform that it had not done during that session.
- In one study to determine a dolphin's ability to remain focused on a task, a program displayed 60 images and sounds for one second each, separated by half second intervals. The dolphins remained focused on identifying the image or sound 95-100% of the time
The following story comes from the Institute for Marine Mammal Studies in Mississippi.
Kelly the dolphin is a thinker. She and her tank mates were taught that when they find a piece of garbage in their tank, they are to give it to the next trainer they see and they will be rewarded with fish. This helps to keep the tank clean. Kelly clearly did some thinking about this. She realized that she would get a reward no matter how big the piece of garbage was. She then began taking large pieces of garbage to the bottom of her tank and hiding it under a rock. When she sees a trainer go by she will simply tear off a piece of the garbage and present it for a fish. In this manner she is showing that she has an understanding of the future and delayed gratification.
Then one day, a gull flew into her pool and she grabbed it. When she presented the gull to her trainer she was given a large amount of fish. This gave her a new plan. The next time she was given a fish, instead of eating it, she hid it under her rock. When none of the trainers seemed to be around, she brought the fish to the surface and used it to lure gulls which would of course, mean a larger quantity of fish! She went on to teach her calf this game, which in turn taught it to other calves.
This study was done by Karen Pryor who is a renowned dolphin expert:
Dolphins in this experiment were rewarded for performing a trick that they had never done before. After a couple of trials, the dolphins finally figured out what was required of them and raced around the tank in excitement, doing more and more unique behaviors. When this trial was carried out on humans, they performed no better than the dolphins had. They even experienced the same period of anger and frustration as the dolphins and showed the same relief when they finally figured it out.
Kewalo Basin Marine Laboratory:
A study was done here to determine if dolphins could understand our language. The trainers developed a sign language to use with the test subjects. They were pleasantly surprised to say the least. The dolphins were not only capable of understanding individual words, they were able to comprehend the significance of word order in a sentence. The dolphin that was most successful at this learned more than 60 individual words and more than 2,000 sentences!
While these are all amazing examples of dolphins showing just how smart they can be, what about the other species of cetaceans? Dolphins tend to be the ideal candidate for these studies primarily because they are of a more manageable size and are easier to care for than their larger relatives. If you would like to see examples of natural intelligent behavior, you will want to read The Awesome Intelligence of Cetaceans Part 2 where you can learn about other cetacean behaviors in the wild and discover further proof that these are remarkable beings worthy of our respect and protection. This information is paired with amazing video footage of many of these behaviors because I believe once you see these beautiful beings doing what they do best, you can't help but understand why they are special.
If you enjoyed this hub you may want to take a look at these:
The Awesome Intelligence of Cetaceans Part 3 - Killer Whales - See for yourself why the Killer whale is the most feared predator for ocean dwelling species. They also have a gentle side, these animals have a complex social structure and most develop bonds with other whales that last for their entire lives. They have also invented many clever ways of catching their favorite foods which include: fish, seals, sea lions, whales (even the great blue whale!) and even sharks!