The young dolphin gives a quick flip of her head, and an undulating silver
ring appears--as if by magic--in front of her. The ring is a solid, toroidal
bubble two feet across--and yet it does not rise to the surface! It stands
erect in the water like the rim of a magic mirror, or the doorway to an
unseen dimension. For long seconds the dolphin regards its creation, from
varying aspects and angles, with its vision and sonar. Seemingly making
a judgement, the dolphin then quickly pulls a small silver donut from the
larger structure, which collapses into small bubbles. She then "pushes"
the donut, which stays just inches ahead of her rostrum, perhaps 20 feet
over a period of up to 10 seconds. Then, stopping again, she regards the
twisting ring for a last time and bites it--causing it to collapse into
a thousand tiny bubbles which head--as they should--for the water's surface.
After a few moments of reflection, she creates another.
This isn't fantasy, it's real. And it isn't magic, just marvelous. It is
a rare dolphin behavior, and we first saw it in the play of two baby dolphins.
It gives us a little more insight into the superb level of control dolphins
can exercise on their water environment, and underscores the fact that we
can still discover things about dolphins by simply watching them.
I first saw this behavior on one of my relatively rare trips out to the
Delphis lab; the project's principle scientist Ken Marten said that "the
two babies, Tinkerbell and Maui" had been doing it for a little while.
My reaction: "Wow, neato. How the heck do they DO that? Try to get
some photo and video shots of it. It sure is cool". Ken, along with
Suchi Psarakos, Research Assistant and computer programmer, did indeed document
the silver rings (although video and photos don't do the rings justice), and this has made it possible to both analyze the physics behind the phenomenon
and to watch the dolphins do this trick in slow-motion.
As it turned out, small silver rings weren't the only toys the dolphins
were making for themselves: some of the creations were as large as a basketball
rim. And Tinkerbell proved able to create a silver helix, spiraling perhaps
20 feet long, that would spring into life in a fraction of a second and
remain stable in the water as she swam past, observing it with sonar and
vision. then--presto! she would grab a small silver ring from the helix
to play with, while the rest of the helix degraded into bubbles which would
belatedly "remember" to rise to the surface.
This was a wonderful mystery to ponder. My attempts at re-creating the rings
in a swimming pool succeeded only in getting water up my nose, but my guesses
were confirmed--with better and more rigorous explanation--by the fluid
dynamics class of Suchi's close friend Hans Ramm at Scripps Institute of
Oceanography.
The silver rings, as it turns out, are "air-core vortex rings",
and the helices are a similar phenomenon. Invisible, spinning vortices in
the water are generated from the tip of a dolphin's dorsal fin when it is
moving rapidly and turning. According to Hans: "Being unstable without
a boundary nearby, the vortex line tends to form into a more stable form
such as a helix. When the dolphins break the line, the ends are drawn together
into closed rings. Owing to the Bernoulli effect, the higher velocity fluid
around the core of the vortex is at a lower pressure than the fluid circulating
farther away. Air is injected into the rings via bubbles released from the
dolphin's blowhole." The energy of the water vortex is enough to keep
the bubbles from rising for a reasonably long period--on the order of 10
seconds. There also seems to be a separate mechanism for producing small
rings, which a dolphin can accomplish by a quick flip of its head.
There is little doubt that this is what is occurring. However, understanding
the physics should not diminish our appreciation of this spontaneous act
of creation by a dolphin mind. These young dolphins have detected, understood,
and manipulated a subtle aspect of their environment, for no reason other
than play.
Creation of these rings by dolphins isn't new. (far from it--dolphins were
probably blowing magnificent silver rings while our anscestors were hanging
off tree limbs). It does seem to be a relatively rare behavior, though:
it has been seen before only in a specific group of dolphins documented
by Diana Reiss and Jan Ostman at Marine World. "The fact that ring-blowing
is rare and that we have two babies doing it suggests that one baby learned
it from the other", comments Ken Marten. "Whether it was a case
of observational learning, or one "taught" the other, we don't
know... but it'd sure be interesting to know."
The social situation also seems to affect ring-blowing: " The babies
made them most intensely when they were the only two dolphins in the tank
and when there was only one adult. The behavior stopped entirely when they
were outnumbered by adults, " observed Suchi. "During one intense
session with Tinkerbell there were often two or three rings visible in the
tank at one time. She frequently swam over to me in an excited state, then
went and made some more."
The reaction to our documentation of these rings has been universal--people
are fascinated by them. Dr. Ken Norris, the world's leading expert on dolphins,
had never seen it before. Robert Wolff of Apple Computer's Advanced Design
Group made a "quicktime" movie of ring-blowing for display on
Mac computers. Arthur C. Clarke, Earthtrust Advisory Board member, thought
they were wonderful--but debated my offered contention that they might
be the first "extraterrestrial art", pointing to interesting "artistic"
achievements by other nonhuman animals.
For myself, I do consider these rings to be "art": the creation
and observation of artifacts by a nonhuman mind, with no use other than
entertainment and aesthetics. One must be constantly wary not to anthropomorphize
the actions of other species--to treat them as though they were human.
But after watching a dolphin create one of these kinetic sculptures--observe it from many angles--and then destroy it with a bite--it seems a long leap of logic to ascribe any other motive.
This can, and will, be debated... but the beauty of the rings is beyond
debate. As evidence mounts for "self awareness" and other "intelligent"
qualities in dolphins, I think that it must cause us again to ask the question:
what are these creatures, that they spin silver lariats for the sheer joy
of creation? And what sort of creatures are we, if we cannot appreciate
and protect them?
