• Why dolphins are deep thinkers

    From Dave Ganz@21:1/5 to All on Fri Oct 14 22:55:03 2016
    XPost: miami.general, alt.sports.football.pro.miami-dolphins, fl.general
    XPost: alt.fishing

    At the Institute for Marine Mammal Studies in Mississippi, Kelly
    the dolphin has built up quite a reputation. All the dolphins at
    the institute are trained to hold onto any litter that falls
    into their pools until they see a trainer, when they can trade
    the litter for fish. In this way, the dolphins help to keep
    their pools clean.

    Kelly has taken this task one step further. When people drop
    paper into the water she hides it under a rock at the bottom of
    the pool. The next time a trainer passes, she goes down to the
    rock and tears off a piece of paper to give to the trainer.
    After a fish reward, she goes back down, tears off another piece
    of paper, gets another fish, and so on. This behaviour is
    interesting because it shows that Kelly has a sense of the
    future and delays gratification. She has realised that a big
    piece of paper gets the same reward as a small piece and so
    delivers only small pieces to keep the extra food coming. She
    has, in effect, trained the humans.

    Her cunning has not stopped there. One day, when a gull flew
    into her pool, she grabbed it, waited for the trainers and then
    gave it to them. It was a large bird and so the trainers gave
    her lots of fish. This seemed to give Kelly a new idea. The next
    time she was fed, instead of eating the last fish, she took it
    to the bottom of the pool and hid it under the rock where she
    had been hiding the paper. When no trainers were present, she
    brought the fish to the surface and used it to lure the gulls,
    which she would catch to get even more fish. After mastering
    this lucrative strategy, she taught her calf, who taught other
    calves, and so gull-baiting has become a hot game among the

    "Intelligence" is a term with many definitions and
    interpretations. It's difficult enough to measure in humans let
    alone other animals. Large brains are traditionally associated
    with greater intelligence, and the brain of the adult bottlenose
    dolphin is about 25% heavier than the average adult human brain.
    Generally though, larger mammals tend to have larger brains, and
    so a more accurate estimate of brain power comes from the ratio
    of brain size to body size - the "encephalisation quotient"
    (EQ). While river dolphins have an EQ of 1.5, some dolphins have
    EQs that are more than double those of our closest relatives:
    gorillas have 1.76, chimpanzees 2.48, bottlenose dolphins 5.6.
    The bottlenose's EQ is surpassed only by a human's, which
    measures 7.4 (Australopithecines - hominids that lived around 4m
    years ago - fall within the dolphin range: 3.25-4.72). But we
    don't know enough about the workings of the brain to be sure of
    what these anatomical measurements truly represent. Today, most
    scientists share the view that it is behaviour, not structure,
    that must be the measure of intelligence within a species.

    Dolphins have invented a range of feeding strategies that more
    than match the diversity of habitats in which they live. In an
    estuary off the coast of Brazil, tucuxi dolphins are regularly
    seen capturing fish by "tail whacking". They flick a fish up to
    9 metres with their tail flukes and then pick the stunned prey
    from the water surface. Peale's dolphins in the Straits of
    Magellan off Patagonia forage in kelp beds, use the seaweed to
    disguise their approach and cut off the fishes' escape route. In
    Galveston Bay, Texas, certain female bottlenose dolphins and
    their young follow shrimp boats. The dolphins swim into the
    shrimp nets to take live fish and then wriggle out again - a
    skill requiring expertise to avoid entanglement in the fishing

    Dolphins can also use tools to solve problems. Scientists have
    observed a dolphin coaxing a reluctant moray eel out of its
    crevice by killing a scorpion fish and using its spiny body to
    poke at the eel. Off the western coast of Australia, bottlenose
    dolphins place sponges over their snouts, which protects them
    from the spines of stonefish and stingrays as they forage over
    shallow seabeds.

    A dolphin's ability to invent novel behaviours was put to the
    test in a famous experiment by the renowned dolphin expert Karen
    Pryor. Two rough-toothed dolphins were rewarded whenever they
    came up with a new behaviour. It took just a few trials for both
    dolphins to realise what was required. A similar trial was set
    up with humans. The humans took about as long to realise what
    they were being trained to do as did the dolphins. For both the
    dolphins and the humans, there was a period of frustration (even
    anger, in the humans) before they "caught on". Once they figured
    it out, the humans expressed great relief, whereas the dolphins
    raced around the tank excitedly, displaying more and more novel

    Dolphins are quick learners. Calves stay with their mothers for
    several years, allowing the time and opportunity for extensive
    learning to take place, particularly through imitation. At a
    dolphinarium, a person standing by the pool's window noticed
    that a dolphin calf was watching him. When he released a puff of
    smoke from his cigarette, the dolphin immediately swam off to
    her mother, returned and released a mouthful of milk, causing a
    similar effect to the cigarette smoke. Another dolphin mimicked
    the scraping of the pool's observation window by a diver, even
    copying the sound of the air-demand valve of the scuba gear
    while releasing a stream of bubbles from his blowhole.

    Many species live in complex societies. To fit in, young
    dolphins must learn about the conventions and rules of dolphin
    society, teamwork and who's who in the group. For these
    dolphins, play provides an ideal opportunity to learn about
    relationships in a relatively non-threatening way. At Sarasota
    Bay in Florida, Randall Wells and his team have observed groups
    of juvenile male bottlenose dolphins behaving like boisterous
    teenage boys. Using its head to do the lifting, one dolphin may
    even get another dolphin air borne, actually tossing it out of
    the water. It's unclear exactly what is going on. It could be
    play, but more likely these are serious interactions that are
    defining social relationships.

    Dolphins gradually build up a network of relationships, ranging
    from the strong bond between a mother and calf, to casual
    "friendships" with other community members. Wells and his team
    were the first to notice that adult male bottlenose dolphins
    tend to hang out in pairs. The dolphins' motivation for ganging
    together is under study but may involve ecological and/or
    reproductive benefits. Dolphins may also form "supergangs".
    Richard Connor and his team in Shark Bay, Western Australia,
    discovered a group of 14 males. The supergang was a force to be
    reckoned with. In the three years it was studied, it never lost
    a fight.

    To keep track of the many different relationships within a large
    social group, it helps to have an efficient communication
    system. Dolphins use a variety of clicks and whistles to keep in
    touch. Some species have a signature whistle, which, like a
    name, is a unique sound that allows other dolphins to identify
    it. Dolphins also communicate using touch and body postures. By
    human definition, there is currently no evidence that dolphins
    have a language. But we've barely begun to record all their
    sounds and body signals let alone try to decipher them. At
    Kewalo Basin Marine Laboratory in Hawaii, Lou Herman and his
    team set about testing a dolphin's ability to comprehend our
    language. They developed a sign language to communicate with the
    dolphins, and the results were remarkable. Not only do the
    dolphins understand the meaning of individual words, they also
    understand the significance of word order in a sentence. (One of
    their star dolphins, Akeakamai, has learned a vocabulary of more
    than 60 words and can understand more than 2,000 sentences.)
    Particularly impressive is the dolphins' relaxed attitude when
    new sentences are introduced. For example, the dolphins
    generally responded correctly to "touch the frisbee with your
    tail and then jump over it". This has the characteristics of
    true understanding, not rigid training.

    Lou Herman and Adam Pack taught the dolphins two further
    signals. One they called "repeat" and the other "different",
    which called for a change from the current behaviour. The
    dolphins responded correctly. Another test of awareness comes
    from mirror experiments. Diana Reiss and her researchers
    installed mirrors inside New York Aquarium to test whether two
    bottlenose dolphins were self-aware enough to recognise their
    reflections. They placed markings in non-toxic black ink on
    various places of the dolphins' bodies. The dolphins swam to the
    mirror and exposed the black mark to check it out. They spent
    more time in front of the mirror after being marked than when
    they were not marked. The ability to recognise themselves in the
    mirror suggests self-awareness, a quality previously only seen
    in people and great apes.

    Not only do dolphins recognise their mirror images, but they can
    also watch TV. Language-trained chimps only learned to respond
    appropriately to TV screens after a long period of training. In
    contrast, Lou Herman's dolphins responded appropriately the very
    first time they were exposed to television.

    Of course, an understanding of TV is of little use in the wild,
    but the ability to respond to new situations has huge
    implications. In the shallows of Florida Bay, Laura Engleby and
    her team have recently discovered an ingenious fishing strategy.
    A number of the local dolphin groups seem to use a circle of mud
    to catch mullet. The action usually begins with one dolphin
    swimming off in a burst of speed. It then dives below the
    surface, circling a shoal of fish, stirring up mud along the
    way. On cue, the other dolphins in the group move into position,
    forming a barrier to block off any underwater escape routes. As
    the circle of mud rises to the surface, the mullet are trapped.
    Their only option is to leap clear out of the water and
    unwittingly straight into the open mouths of the waiting

    There is still much to learn about these flexible problem-
    solvers, but from the evidence so far, it seems that dolphins do
    indeed deserve their reputation for being highly intelligent.

    More on dolphin intelligence

    The dolphin who loved me: the Nasa-funded project that went wrong
    Whales and dolphins 'should have legal rights'
    Let's talk dolphin!

    Zoologist Anuschka de Rohan produced last month's Wildlife on
    One programme, Dolphins - Deep Thinkers? This piece is based on
    an article in the July issue of BBC Wildlife Magazine, available
    from newsagents or BBC Wildlife Magazine Subscriptions on 01795


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