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Old 12-27-2008, 03:56 PM   #1
Potemkin
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Default Tool using dolphins discovered

http://online.wsj.com/article/SB1230...011.html?print

Among Dolphins, Tool-Using Handymen Are Women
In a Sign of Animal Ingenuity, the Marine Mammals -- and One Cross-Dresser -- Are Seen Making Hunting Implements

*
By ROBERT LEE HOTZ


In the deep, lucid channels of Australia's Shark Bay, wild bottlenose dolphins have discovered tools, raising provocative questions about the origins of intelligent behavior, the nature of learning and the birth of technology.

There, dolphins in one extended family routinely use sponges to protect their noses as they forage for fish hidden in the abrasive seafloor sand, Georgetown University scientists reported earlier this month.
Sponges as Tools

One of the few male spongers with a bright orange sponge.

As best the researchers can tell, a single dolphin may have invented the technique relatively recently and taught it to her kin. The simple innovation dramatically changed their behavior, hunting habits and social life, the researchers found. Those that adopted it became loners who spend much more time on the hunt than others and dive more deeply in search of prey. The sponging dolphins teach the technique to all their young, but only the females seem to grasp the idea.

"It is indisputably tool use," says primate anthropologist Craig Stanford at the University of Southern California, an authority on animal cognition and behavior who wasn't part of the dolphin research group. "Despite the fact they lack hands and legs, dolphins make do."

For those seeking a glimpse of our own beginnings, the dolphins of Shark Bay offer a hint of the inventive impulse when our earliest ancestors first shaped destiny by fashioning implements with their own hands.
Recommended Reading

Georgetown University marine biologists report on "Why Do Dolphins Carry Sponges?" this month in the online journal PLoS One.

In 2005, researchers at the University of New South Wales ruled out genetic explanations for the dolphins' tool-using behavior in "Cultural transmission of tool use in bottlenose dolphins," published in the Proceedings of the National Academy of Sciences.

Last year, Iowa State University researchers reported in "Savanna Chimpanzees, Pan troglodytes verus, Hunt with Tools," published in Current Biology, that some chimpanzees use spear-like sticks to hunt.

The controversy over tools and culture among animals is reviewed by scientists at the University of St. Andrews in "The animal cultures debate," published in the journal Trends in Ecology and Evolution.

The Dolphin Brain Atlas is maintained online at the University of Michigan's Brain Biodiversity Bank.

Dolphin biologist Maddalena Bearzi and primatologist Craig Stanford explore the similarities in tool use and other cognitive abilities among apes and dolphins in "Beautiful Minds: The Parallel Lives of Great Apes and Dolphins."

Pioneering neuroscientist Michael Gazzaniga covers the molecular biology, genetics, evolutionary and cognitive psychology that set people apart from other creatures in "Human: The Science Behind What Makes Us Unique."

Tool use of any sort among wild animals is rare, difficult to document reliably and controversial. The line between instinct, ingenuity and intelligence is easily blurred by wishful thinking, experts caution. Field observations are often fodder for scholarly disputes. Even so, 10 primate species of monkeys and apes, along with 30 species of birds, are thought to use sticks, rocks or leaves as tools at least every once in a while.

Sea otters deliberately batter abalone shells with rocks to obtain the succulent meal inside. Some crabs, like shoreline seamstresses, cut up sponges and wear them for camouflage. Wild chimpanzees in Senegal hunt bush babies with makeshift spears, researchers at Iowa State University reported last year. Caledonian crows fish for insects with grass stalks and strips of leaves, while woodpecker finches hunt grubs with a cactus spine. Humpback whales weave nets of bubbles to snare fish in what some marine scientists contend is a form of communal tool use.

In the first in-depth analysis of this natural dolphin behavior, published in the online journal PloS One, marine biologist and psychologist Janet Mann at Georgetown University and her colleagues found that the dolphins of Shark Bay use their makeshift hunting masks more often than any other species uses tools, save human beings. "Tool use among this population is striking," says Dr. Mann, who has studied these marine mammals in the wild since 1989. "Spongers use tools more than any nonhuman animal."

The curious hunting habit first came to light decades ago when a local bay fisherman mentioned to marine biologist Rachel Smolker that he had seen a dolphin with an odd growth on its nose. Monitoring its movements through the bay's unusually clear waters, the researchers soon discovered that the sleek, air-breathing mammal was actually balancing a conical basket sponge on its beak.

At first, no one could figure out what a dolphin was doing with a sponge. From their vantage aboard a small dinghy, Dr. Mann and her colleagues eventually identified 41 dolphins who regularly used sponges to hunt, cataloging 1,295 dives in which they surfaced with sponges on their snouts.

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Other forms of animal ingenuity have been observed in sea otters

Other forms of animal ingenuity have been observed in sea otters, who use rocks to open shells.
Other forms of animal ingenuity have been observed in sea otters
Other forms of animal ingenuity have been observed in sea otters

Researchers were startled to realize that the dolphins of Shark Bay employed one living creature as a tool to help hunt another.

Not any basket sponge would do, the researchers soon learned. The dolphins might search for 10 minutes to locate one with the right conical shape to cap their nose, tear it free of its mooring, and then carry it to a preferred hunting ground along channels between 26 feet and 42 feet deep. "You can see that they are scattering the sand gently as they go along," says Dr. Mann. "When they startle a fish out of the sand, they immediately drop the sponge and go after it." They return to retrieve the sponge and pick up the hunt again, repeating the pattern.

"They really use these sponges as a foraging tool," says dolphin biologist Maddalena Bearzi, president of the Ocean Conservation Society in Los Angeles. "They discovered it could create an advantage in their foraging technique, and they pass it from generation to generation."

Only a few dozen dolphins use sponges to keep from scraping their noses, among the hundreds living in the bay, and that offered researchers an opportunity to compare creatures that use tools to others of the same species that do not.

Although the wild spongers all appear to be related, researchers at the University of New South Wales suggest that nurture, not nature, is the reason these dolphins use tools, ruling out genetic explanations for the behavior. Instead, they are convinced that sponging is passed from one generation to the next through the rote learning of imitation. Among bottlenose dolphins, mothers nurse their young for up to eight years, ample time for calves to absorb their mother's hunting tricks by observation. "This is an example of culture among these animals," says Dr. Bearzi. "This is part of the reason it is so important."

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Chimpanzees

Chimpanzees use spears to hunt.
Chimpanzees
Chimpanzees

So far, almost all of the dolphin spongers have proved to be female. "The sex difference is really striking," Dr. Mann says. "I don't know of another species where it is so dramatic."

Of the spongers' offspring, only the daughters could be seen still sponging once they reached maturity. The sons tried it but almost always abandoned it. Male dolphins rarely play a role in child-rearing and tend to fish in packs.

Only one older male dolphin continued hunting with a sponge. "He would go get a sponge and do it privately," Dr. Mann says. "It was like he was cross-dressing in private -- an old man out there sponging by himself."

For Dr. Mann, the discovery that dolphins too are tool users adds an unexpected dimension to the history of innovation, shedding new light on animal intelligence. Clever mimics and fast learners, dolphins have unusually large brains -- four times the size of a chimpanzee's and second only to humans in relative size. Dolphins even show evidence of self-awareness, by being able to recognize themselves in a mirror, some scientists argue.

"It speaks to this whole issue of creativity and learning and brain size," she says. "The number one question that drives me and others is, Why do dolphins have such big brains? What are they doing down there in the water that requires them to be so smart?"
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Old 12-27-2008, 04:52 PM   #2
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maybe it's not seen as "manly" for male dolphin to need a nose sponge.

Last edited by flourbug; 12-28-2008 at 10:45 AM. Reason: I follow you, fixoring your typos.
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Old 12-28-2008, 10:33 AM   #3
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Birds at my feeder take a sunflower seed to a nearby tree branch and hammer it to break the shell so they can eat it. This is not different from a handed creature hitting it with a rock.

Animals display intelligence to us, the most casual observers, all the time. But scientists are amazed whenever they spot another demonstration of it.

OH
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Old 12-28-2008, 11:02 AM   #4
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Our dog sword fights with our son. When he gets tired of being the dragon that gets slain, the dog wrestles the sword (or lightsaber) away and chases the kid around the house, smacking him with his own weapon.

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Old 12-28-2008, 12:32 PM   #5
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Right on FB! The game playing that dogs love is an excellent example of intelligence.

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Old 12-28-2008, 04:05 PM   #6
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Quote:
Originally Posted by Old Hawk View Post
Right on FB! The game playing that dogs love is an excellent example of intelligence.
Let your don't see you put 3 doggie biscuits in your pocket and only feed him two.

See what he does.

Dogs know math.
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© Gregori Potemkin. All rights reserved. But wait . . . fair use allowed and encouraged. Actually, go 'head and publish the whole thing as is. I don't care.
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