The Dolphin in the Mirror (20 page)

Presley with a nontoxic mark on his head in the mark test.
AUTHOR

Reflecting on himself.
AUTHOR

Dolphin admiring her own creation, an exquisite bubble ring.
AUTHOR

After the MSR paper was published, the dolphins continued to get mirrors as enrichment objects.
AUTHOR

One of the first hurdles in the rescue. Tense times as Humphrey stopped and refused to swim through the pilings at the Liberty Bridge.
ASSOCIATED PRESS

Humphrey follows the
Bootlegger
back out to sea.
ASSOCIATED PRESS

Despite press conferences (here, at the National Press Club, with leading marine biologists and veterinarians), diplomacy, and public pressure, the drive hunts continue.
AUTHOR

After the film
The Cove
was released, the dolphin slaughtering was moved under tarpaulins, to try to hide it from any rogue cameras.
HELENE O'BARRY/DOLPHIN PROJECT

"W
HAT ARE THEY DOING
?" I exclaimed to no one in particular. I was perched on the observation deck overlooking one of the pools at Marine World, monitoring Delphi and Pan in the water below. The two young males, now seven years old, were engaged in sexual behavior, belly to belly. To put it technically, they were attempting intromission. In general, for bottlenose dolphins, copulation is the culmination of an aquatic courtship dance that I think they start to learn in the first few weeks of their lives—from their mothers.

I had been fortunate to be able to observe very closely the mother-infant interactions with Delphi and his mother, Circe, and with Pan and his mother, Terry, pretty much from day one. It was quite fascinating and revelatory—and it changed the way I viewed dolphin behavior from that time on. The behavior patterns that I saw with Terry and Pan were usually repeated within a few hours or a day later by Circe and Delphi. Whether that repetition was programmed, as Delphi was a day younger than Pan, or whether Circe was learning from the more experienced Terry, I can't really say.

In the first few weeks of life, calves, who don't yet have full coordination of swimming and breathing, swim right next to their mothers. This is called echelon swimming. In the mother's slipstream, the calf gets a bit of a free ride, expending less energy during the early weeks of life. Slipstreaming also keeps the calf in close proximity and tightly coordinated with its mother's movements. Newborn dolphins are born without much blubber—a layer of insulation made up of fat and fiber, riddled with blood vessels, that helps dolphins and whales thermoregulate in cold and warm waters. This fatty layer provides a storehouse of energy for these mammals for foraging, migrating, and breeding. It also helps make them buoyant in water. The blubber layer is built up as the calf nurses on its mother's milk, which is 10 to 20 percent fat and rich in calories.

As the calf gradually gains better control over its breathing, it begins to swim just underneath the mother. We call this the baby position, and it has two big benefits. It facilitates nursing from the mammary slits that flank both sides of the genital slit, at the narrowing end of the mother's underside where belly meets tail. Also, it may confer some camouflage from potential predators below. In the vulnerable first weeks of life, the light underside of the calf may be less visible when it's silhouetted against its mother's light underside.

During these first weeks the babies begin to get bolder, darting off on little excursions of their own, forgetting that they haven't yet learned how to stop or return to their moms. The mother quickly swims after her calf and reestablishes the echelon or baby position. In the following weeks the calf learns to stop and return to its mom, and to swim in circles around her. Dolphins are social learners, observing, listening, and imitating what they see and hear. Whether adult dolphins or whales intentionally teach specific skills to their young remains unclear. Hal Whitehead and Luke Rendell have described what indeed seemed to be a case of such pedagogy in orcas, killer whales, who appeared to instruct younger orcas in predatory methods and maneuvers.
¹
Terry and Circe, too, exhibited several instances of what could be loosely interpreted as instruction during the early mother-and-calf interactions.

For example, I observed Terry stop as Pan continued to move forward past her head, whereupon she pushed him backward with her rostrum, and positioned him perpendicular to her in what looked like a T formation. She then nuzzled his genitals with her beak. Terry patiently repeated this behavior with Pan: stopping, allowing Pan to go forward by himself, and then stopping him with her rostrum. She repeated this many times until Pan got the hang of putting his aquatic brakes on. A day later I saw Circe do the same sequence with Delphi. The calves began to stop on their own in the T position, lying on their sides, completely still. I called this the dead man's float (another of my highly inventive technical terms). As a reward, they received genital nuzzling from their mothers.

Very soon the babies became even more adventurous, embarking on more extensive forays on their own, which led to a game of chase; the mothers would swim after the calves, corral them, and bring them back. Before long, the babies learned how to circle back on their own, and the chase developed into what I called a figure-eight swim, which is exactly what it sounds like. The big adult and the diminutive calf chased each other in a figure-eight path, occasionally porpoising, or arching clear of the water in repeated jumps. During the chase the pursuing mother would sometimes approach her calf from behind and nuzzle his genital area with her beak.

Next, Delphi and Pan, in their initial and continued forays with each other during their first six months of life, did the same tango sequence with each other—the chase, the figure-eight swim, the dead man's float, the beak-genital nuzzling. Eventually, it culminated in what looked like sexual behavior. One of the boys would approach the other from behind and below and attempt to copulate with him. Dolphins copulate belly to belly. The boys would often switch roles, one pursuing, the other pursued.