The Dolphin in the Mirror (8 page)

By an interesting coincidence, Betty's lagoon was just a short distance from where, a decade before I arrived, the
Flipper
television series had been filmed. As it happened, Betty had acquired her dolphins through the same people that captured the dolphins for the show. Visiting Betty was like having Flipper in my backyard! How ironic, given my lack of regard for the
Flipper
series yet my passion for studying the real thing.

During that first week of quiet observation and the subsequent weeks of more directed study, I noticed how very social the dolphins were, not just with each other but also with me. I quickly realized (actually, it was an uncanny
feeling
) that in the same way I was observing them, they were observing me. They made extraordinary direct eye contact. I got a powerful sense of a very real presence there.

It was impossible to ignore. They seemed to deliberately engage me in games, such as the seaweed game, in which they'd take mouthfuls of seaweed, come to the side of the lagoon where I was sitting, and flip the seaweed to me. It was obvious what I was expected to do: flip it right back. I was essentially imitating what they were doing. This back and forth, back and forth might go on for several minutes. I imitated other behaviors too. For instance, they would occasionally lie on their sides and look up at me, and I would then do the same thing, lying on my side and looking down at them, trying to match their posture and body orientation. What might seem like trivial behavior patterns have elements that are profound. The initiation and imitation was establishing a basic level of communication, one species to another: I see you. I acknowledge you. I'm doing it back. From the beginning I was guided by a simple rule: All animals communicate, and we can communicate with other animals. It is not a matter of
whether
we can communicate; it is a question of
how
. And here, by the lagoon, an instance of "how" was emerging.

***

Dolphins
^*
have a certain ineffable presence about them, which is partly what draws people to aquariums and drives them to seek swim-with-dolphins experiences. Despite this visceral connection, people recognize how different humans are from dolphins in physical form and, of course, in aquatic abilities. But most people are unaware of how very different dolphins are from humans in mundane realms, such as breathing and sleeping and the perception of their environment.

I'll start with the differences in how dolphins and humans breathe and sleep, which, odd as it might seem, are actually closely linked. A dolphin breathes through a blowhole that is positioned on the top of the head, an important aspect of dolphins' evolution from land animal to marine mammal. The nostrils of dolphins' ancestors slowly "migrated" from the front to the top of the head. Nostrils atop one's head makes breathing easier during swimming or resting at the surface. Having your nostrils on top of your head might seem bizarre, but that is not the most important difference between us and them. The most important difference is the
manner
in which dolphins breathe. For humans, and for most terrestrial mammals, breathing is an involuntary process. The rate and timing of human breathing is governed by receptors in the brain that monitor the level of carbon dioxide in the blood and respond appropriately. Humans don't have to think about it. But for an air-breathing mammal who spends most of its time underwater, exactly
when
it breathes can be a matter of life or death. When receptors in a dolphin's brain indicate it needs to breathe, the dolphin must first swim to the surface. In other words, for dolphins, breathing is a voluntary process, not an involuntary one.

A human wouldn't make a very good dolphin because he or she would have to surface half a dozen times each minute to breathe, which would be very inconvenient for a creature that forages and conducts its social life underwater. Dolphins, however, are superbly adapted to life under the waves. Under normal circumstances, they breathe two to four times a minute, although they can hold their breath as long as fifteen minutes; they exhale (just as they reach the surface) and inhale in a fraction of a second; they exchange up to 90 percent of the air in their lungs, compared with our much more limited 10 percent; and they extract much more oxygen from each breath than we do. The anatomy and physiology of their breathing is much more efficient than ours.

So when we ask what it's like to be a dolphin, part of the answer is that they have to think about breathing. Also, they sleep very differently than we do. All mammals sleep, and dolphins are no exception. When humans go to sleep, we become unconscious, and our physiological systems run on autopilot. Dolphins have no such autopilot; at least, not in the realm of sleeping. To keep the dolphin from drowning, there has to be some part of the dolphin brain that remains awake. And yet, they also need to sleep. How do they do it? Dolphin brains, like ours, are divided into two hemispheres. When we humans sleep, both hemispheres go into unconscious mode. Through evolution, dolphins have arrived at another strategy: one hemisphere sleeps or rests while the other maintains breathing duties, motor behaviors, and possibly also some vigilance against predators. When dolphins are in sleep mode they often lie motionlessly at the water surface or at the bottom of a pool, or they might swim slowly, sometimes with one eye closed, surfacing from time to time to breathe. Dolphins appear to sleep or rest many times throughout the day and night. We don't know if they dream.

Another big difference is in how they perceive the world. Dolphins, like us, face complex environmental and social challenges, and they use their senses and perceptions to survive and thrive in their dynamic environment. Dolphins use a rich constellation of multisensory signals to communicate with one another, including acoustic, visual, tactile, and possibly chemical (taste) signals. In the course of the dolphins' adaptation to a totally marine existence, they have evolved specialized sensory systems that enable them to perceive their world even when vision is limited and vast distances separate them. Dolphins have the basic senses of hearing, vision, touch, and taste, but they have lost their olfactory receptors and the olfactory areas in the brain—thus they are unable to smell. Terrestrial mammals use scent trails and territorial scent marks, but these do not exist in the aquatic world, and the unneeded sense was eventually lost.

The visual systems of animals are adapted to each species' environmental requirements. As primates, humans have excellent vision (not as good as some birds', of course), and it is our primary sensory guide in the world. Humans, like most other primates, have trichromatic vision; this means the eye has three types of color cones, enabling an individual to perceive a myriad of colors. The dolphins' sensory world is highly acoustic, so many people believed that they had inferior visual abilities. But in fact, dolphins have excellent vision. Although they are monochromats—they have only one type of color cone, and thus are colorblind—they are very sensitive to light in the blue region, which is the color of their aquatic world. The dolphin eye has many more rod cells than the human eye, making it very sensitive to low-light conditions, an important adaptation for life in the sea. Underwater, a human can't see very well without a facemask, but the lens of the dolphin eye is highly specialized and affords the dolphin vision that's just as good in the air as it is in the water.

Humans have at best a mediocre sense of hearing when compared with that of many other animals, but our hearing really pales in comparison to the acoustic processing abilities of dolphins. Their marine world is filled with sound; sounds travel farther and about 4.3 times faster in water than in air. Our world is made up of visual images; the dolphins' world is one of acoustic images, as well as images.

For creatures whose perceptual world is so dominated by sound, the absence of any obvious external ears might seem odd. The ears have been lost over evolutionary time, sacrificed in the radial streamlining of their bodies in their adaptation to a superbly efficient hydrodynamic physical form. (Dolphins are one of the swiftest creatures in the oceans.) The external ears have vanished, but the inner ears are present and again exquisitely adapted to the species' needs. For instance, dolphins can locate the source of a sound underwater, which humans find almost impossible, and their range of hearing is much greater than ours—it stretches from 150 to 150,000 Hz or higher, compared with humans' 20 Hz (a little lower than the first key on a piano) to 20,000 Hz (about two octaves higher than the last key on a piano). It is their high-frequency range that also sets dolphins apart from humans.

In the course of evolving into fully aquatic mammals, dolphins have developed an exquisite and highly sophisticated biosonar system known as echolocation that allows them to navigate in a world without particularly good vision. It's a biological version of man-made radar and sonar, but much more powerful. (Dolphin echolocation is the envy of the military.) Dolphins have air sacs beneath their blowholes, and a dolphin echolocates by moving air between these air sacs at an extremely fast rate; this produces rapid sequences of high-frequency clicks, each of which lasts less than a thousandth of a second, that are directed forward in a narrow beam (the beam is shaped partly by the contours of the dolphin's bony skull and partly by a fatty "melon" that acts as an acoustic lens to focus sound). When the sound waves hit a solid object, echoes bounce off the object, travel back to the dolphin, are collected through the bones of the lower jaw (and a few other areas of the body), and are transmitted to the inner ears.

The numbers here are impressive. Dolphins can produce from as few as eight clicks a second, which sounds like a creaking door, to as many as two thousand clicks a second, which sounds like a high-pitched buzz. Individual clicks are wide-band sounds, composed of a rich mixture of low- and high-frequency wavelengths. The low-frequency clicks are longer wavelengths; they travel farther and give the dolphin a general overview of an object. The high-frequency clicks are shorter wavelengths; they don't travel as far but they provide more details. One might expect the returning echoes to produce a confusing cacophony impossible to interpret. But in fact, the dolphin receives a clear acoustic image of its surroundings. Dolphins can almost literally see with sound. And as I mentioned above, the exquisite degree of image discrimination has navy technicians salivating. To give just one example: at a distance of thirty feet, a dolphin can detect a few tenths of a millimeter's difference (about the thickness of a fingernail) in the density of the walls of two metal cylinders.

In addition to being highly sensitive to sound and visual images, dolphins are highly sensitive to touch. Touch plays an important role in human social interactions and relationships, and the same seems to be true in dolphin societies. Dolphin social behavior frequently involves tactile interactions such as pectoral-fin rubbing, pectoral-to-pectoral fin contact while swimming (it looks like handholding!), and body rubbing. It's been reported that the level of tactile sensitivity on some areas of the dolphin body is comparable to the sensitivity of our fingertips and lips.

Imagine being able to control your breathing and hold your breath for astonishingly long periods; imagine sleeping half a brain at a time; imagine acoustically "seeing" finely detailed images of distant objects in complete darkness with your biological sonar. It has been suggested, although not verified, that dolphins have the ability to image the internal bodies of others, so imagine having x-ray vision and being able to scan the internal bodies of your family members and friends; you'd know about all their pregnancies, injuries, and illnesses. Imagine, too, that your environment is the ocean and that you are the king or queen of speed. That—in part, at least, and from a limited viewpoint—is what it might be like for a human to be a dolphin. But how can anyone really know what it's like for a dolphin to be a dolphin? My goal was to get a glimpse of that by opening a window into the dolphin mind.

***

When my month at Little Torch Key was over, I hadn't discovered any significant insights into the cognitive or communicative abilities of dolphins. But I had accomplished my research goals for the project: I'd learned the technical aspects of recording dolphin vocalizations using specialized underwater equipment, and I had a car full of large reels of tape with recordings of those vocalizations to take back to the university for analysis. I had put the equipment to good use, recording their different sounds and testing to see if Dal or Suwa used specific types of vocalizations when fed or when presented with a particular object, such as a ball, a ring, or a seashell. I had not collected publishable observations during that month, yet the experience was an invaluable foundation for work that, I hoped, would eventually merit publication in scientific journals. The experience also left me with more questions than I'd started with, and for that I was thrilled. For a scientist, knowing the questions to ask is as important as finding the answers (and sometimes more important).

On a personal level, Dal and Suwa provided my first encounter, and I experienced a sense of their intelligence. It wasn't just the experience of being held in an uncanny gaze; it was a sense of a familiar presence in these creatures, a manifestation of the pattern that connects. But I was unsure of my next steps. I wished I had the seal of Solomon, a signet ring that was said to give King Solomon the power to communicate with other animals. Konrad Lorenz, the famous German ethologist, had claimed to accomplish this feat, not by using Solomon's ring but by using his own powers of observation of the animals around him. If you pay close attention to their interactions with one another and with you, animals will often reveal their secrets.

Toward the end of the month, I had taken to amusing myself in the evenings by playing my flute by the lagoon. It was simply for relaxation, although it was romantic in the purest sense, there by the water's edge with the western sky still brushed crimson from the sunset. To my surprise, I began to get the impression that Dal and Suwa were paying attention to my playing. I discovered by simple experimentation that if I picked up the tempo, they swam faster. And if I played slowly, they became somewhat languorous.
^*
I remember thinking on one such evening,
Wow, here I am studying dolphins, looking out at the open ocean and playing my flute, which these creatures are responding to from their inner nature. I am the luckiest person in the world!
I was hooked.