Last Friday, the wondrous Emily Anthes at Wonderland posted a spellbinding SeaWorld video of dolphins blowing ring bubbles. Go—I command you!—to Wonderland now and watch that video. But then come back—I implore you!
Emily’s post reminded me of one I wrote way back in 2005, at the short-lived SA Perspectives blog I started as a covert project to demonstrate the value of blogging to Scientific American‘s management. (Well, that, and to have a place where I could write on my own.) I’ve dusted it off, lightly cleaned up some dead links and other infelicities, and offer it to you now. Remember, everything here is old information; please feel encouraged to offer updates or to answer any of my meandering questions and speculations in comments.
Herewith, from June 20, 2005, my reflections on ring bubbles and culture among dolphins and whales.
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As you may recall, a few weeks ago Michael Krützen and his colleagues reported in the Proceedings of the National Academy of Sciences that dolphins from Shark Bay in Australia seem to have a material culture. Within this community of dolphins, some of them (mostly females) have learned to wear protective caps of sponge on their noses while rooting through the seafloor to stir up prey fish. This behavior seems to be passed on from mothers to offspring through learning, not any identified genetic predisposition, and may be traceable back to some “Sponging Eve” who first developed the technique in the not-too-distant past.
Interest in dolphin intelligence used to concentrate on their communication abilities and the possibility that they had some form of language. Language, of course, is a manifestation of our human intelligence, too. Nowadays the focus has shifted to other behaviors, which seems wise for helping to overcome our anthropocentric biases in making sense of other creatures. Nevertheless, I can’t help but wonder whether we are still blinkered in our views of them.
For example, one of the most widespread interpretations of the Krützen study has been this [dead link to Discovery.com]:
The use of sponges as tools among some dolphins could be the first documented case of a material culture in a marine mammal species.
In recent years, researchers at several oceanariums around the world have reported that a variety of marine mammals can blow smooth, stable rings of air that linger in the water for several seconds. Because of the intricate techniques and practice required to form such rings, as well as the helices we have seen, these bubbles are clearly not a spontaneous response to alarm or a standard part of communication.
They list some amazing reports of ring bubble-making behaviors by captive Amazon river dolphins, bottlenose dolphins and beluga whales, as well as by some Pacific and Atlantic spotted dolphins and belugas in the wild. They continue:
[We] believe ring blowing is more common at Sea Life Park Hawaii than at other aquariums; the dolphins here appear to have created a “ring culture” in which novice dolphins learn to make rings in the presence of experts that, in a sense, pass down the tradition.
Ring making is a leisurely pastime, so the animals generate rings only when they want to—not on command or for a reward of food. Furthermore, ring making does not seem to be associated with functional behaviors such as eating or sexual activity. Because ring blowing is unpredictable, we have had some difficulty documenting it. But over time we have captured most of the dolphins at play in photographs and on videotape.
…On a few occasions, we watched the young female dolphin Tinkerbell, Laka’s daughter, construct long helices of air, using the most complicated technique we have seen. These more complex structures no doubt result from considerable refinement through trial and error….
…Although we did not see any dolphins other than Tinkerbell generating helices, the practice of making rings spread through the population of dolphins, as some of the individuals learned the technique in the presence of their ringblowing companions. We had the opportunity to watch one young dolphin’s rings evolve over a period of two months from unstable, sloppy bubbles that dissipated rapidly to stable, shimmering rings that lingered in the water for several seconds. Older dolphins also needed time to acquire the talent. One adult male, Keola, lived in the research tank for two years with dolphins that did not produce air rings, and during that time we did not see him generate any. But when his younger, ring-blowing sibling Kaiko’o moved into the same tank, Keola watched for long stretches while Kaiko’o blew rings; within a couple of months, Keola began making his own rings, which slowly progressed in quality.
So it seems to me that these dolphins were also purposefully manifesting an acquired skill for manipulating material, and that they transmitted this skill throughout their group and across generations–is that enough for a material culture?
Someone more knowledgeable may be able to point out why it’s not. My suspicion, though, is that the ring-bubble behavior is brushed aside for two reasons.
- Play, which seems to be the dolphins’ reason for blowing the bubbles, does not seem like a respectably serious behavior, as the Shark Bay dolphins’ sponge use while hunting does.
- Bubbles don’t seem “material enough” to count toward material culture.
Similar anthropocentric attitudes have also influenced the debate over whether humpback whales show cultural activity in their singing. As Roger S. Payne of the Ocean Alliance has documented, the whales pick up elements from one another’s songs and remix them in original ways; to what end, no one entirely knows. I believe Payne has even observed that the songs of whales from the 1960s were more aesthetically pleasing—to us—than modern ones, which shows how plastic their singing can be. And yet the argument that whales exhibit an oral culture continues to be controversial.
Songs, play and bubbles are far more central to the lives of dolphins and whales than to us, and we should maybe be more willing to let them be yardsticks for measuring their way of life. We can scarcely imagine what the world looks like to cetaceans. Their sonar and the sensitivity of their skins to vibrations in the water may lend an extraordinary immediacy to their experience of their surroundings. Bubbles, for us, are airy nothings but for them they could be substantial, dynamic forces. And in fact, several species of cetaceans—humpbacks and some smaller dolphins, for example—have been seen to use bubbles to help shepherd fish while they are hunting cooperatively.
That alienness was captured in Ted Mooney’s novel Easy Travel to Other Planets, best remembered for introducing the term “information sickness” and for its scenes of a woman having a (*cough*) sexual relationship with a dolphin. My copy of it is unfortunately boxed away in storage right now and so I cannot quote it properly, but after 20 years I still recall the poignance of the opening paragraphs in which a dolphin cruises through a bay at night, feeling a shrimp fisherman setting his nets from miles away and pondering the tidal tug of the moon, the place where dreams come from.
Another thing: As mentioned above, the use of sponges by the Shark Bay dolphins is primarily, but not exclusively, a female behavior. At least one of the many stories on this work included speculation on why.
“It seems highly likely that sponging is culturally transmitted mainly within a matriline, ie, daughters learn this behaviour from their mothers,” reports lead author Dr Michael Krützen, who did the work while studying for his PhD at Australia’s University of New South Wales.
Male dolphins have the same opportunity as their sisters to learn the trick, but apparently have better things to do, he suggests.
… [University of New South Wales geneticist Associate Professor William] Sherwin says we don’t know why female dolphins sponge.
“It may be that the males just don’t want to learn,” he says.
Some researchers also believe that male dolphins have the most complex interactions of any animal apart from humans, and Krützen supports the ‘busy social life’ theory.
“Sponging is time-consuming solitary activity that may not be compatible with the requirement for males to associate at high levels with … partners,” he says.
This explanation is reminiscent of the evolutionary one often floated for ostensible differences in the behaviors of human males and females, but with the sex roles reversed. Among the dolphins, it’s the females that have the heavy hunting responsibilities and become the comparatively anti-social loners, while the males are the gregarious ones devoting their lives to cultivating rich social lives. But is it my imagination or do the males in both scenarios somehow always sound more autonomous than the females?
“Mystery of the Silver Rings,” by Don White, creator of Project Delphis.
Bubblerings.com on Dolphins and Whales.
“Sponge-Nose Smarty Pants,” by JR Minkel. [A short news item with a wonderful title written by JR, whom I eulogized last week.]