Fish puke, bread grunts and other signs of culture

O.K., “Free Willy” fans! Time for another heart-warming story of a captive killer whale who is really just like us. We could call this one “Free Lunch”:

First, the young whale spit regurgitated fish onto the surface of the water, then sank below the water and waited.

If a hungry gull landed on the water, the whale would surge up to the surface, sometimes catching a free meal of his own.

Noonan watched as the same whale set the same trap again and again.

Within a few months, the whale’s younger half brother adopted the practice. Eventually the behavior spread and now five Marineland whales supplement their diet with fresh fowl, the scientist said.

“It looked liked one was watching while the other tried,” Noonan said of the whale’s initial behavior.

The capacity to come up with the gull-baiting strategy and then share the technique with others — known as cultural learning in the scientific world — was once believed to be one of those abilities that separated humans from other animals.

But biologists have since proven certain animals, including dolphins and chimps, do this.

“This is an example in which a new behavior spread through a population,” Noonan said. “We had the opportunity to see a tradition form and spread in exactly the way that cultures do in humans.”

A more sober article in New Scientist summarizes this and several other recent examples of cultural learning, including a new study on chimps:

Chimpanzees appear to be capable of communicating using sounds that refer to specific objects, according to a study of sounds made in response to different foods. It is the first time this ability has been demonstrated in chimps.

Primatologist Katie Slocombe of the University of St Andrews, UK, recorded the grunts made by chimps at nearby Edinburgh Zoo as they collected food at two feeders. One dispensed bread, considered a high-quality treat, and the other doled out apples, a much less sought-after snack.

Slocombe then played back the recordings and watched the reactions of a 6-year-old male named Liberius. The results were striking. After hearing a bread grunt, Liberius spent far more time searching around the bread feeder, while an apple grunt would send him hunting under the apple feeder. Slocombe presented the work at the US Animal Behavior Society meeting in Snowbird, Utah, this month.

This is the first convincing evidence of “referential communication” in chimps, says primatologist Amy Pollick of Emory University in Atlanta, Georgia. Earlier research with a close cousin of the chimpanzee – a male pygmy chimpanzee, or bonobo, named Kanzi – showed that he made specific sounds for four different things: bananas, grapes, juice and yes. But the researchers did not test if the sounds conveyed any meaning to other bonobos, and the same experiments have never been done in chimpanzees.

Liberius, on the other hand, was able to take cues from apple and bread grunts made by at least three different chimpanzees.

This follows closely on the heels of another report of cultural learning among captive chimpanzees. I imagine that in a few years there will be dozens of other examples from many different species of mammals and birds, now that the taboo against studying animal cultures seems finally to have been lifted.

But here’s what I wonder. Suppose the “Free Willy” crowd organizes for the release of the Marineland orcas back into the wild, and they then transmit their new-found bait-and-snatch lore to other killer whales. What will this do to wild populations of seabirds? Will they all prove equally, um, gullible? Take fulmars, for instance. Their diet is described as “oily offal and refuse, fish and cuttles.” Seems as if they might be at high risk here – except that nature (or culture?) may have left them well equipped to retaliate. “Fulmar” means “foul gull” in Icelandic. When disturbed, fulmars hurl a stream of bright-orange, foul-smelling projectile vomit with great accuracy into the eye or other orifice of their attackers. Things could get interesting out on the high seas.

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Dave Bonta (bio) crowd-sources his problems by following his gut, which he shares with 100 trillion of his closest microbial friends — a close-knit, symbiotic community comprising several thousand species of bacteria, fungi, and protozoa. In a similarly collaborative fashion, all of Dave's writing is available for reuse and creative remix under a Creative Commons Attribution-ShareAlike 3.0 United States License. For attribution in printed material, his name (Dave Bonta) will suffice, but for web use, please link back to the original. Contact him for permission to waive the "share alike" provision (e.g. for use in a conventionally copyrighted work).

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