Can monkeys mislead?

Capuchin monkeys cry "predator" to trick more senior members of their troop into fleeing the dinner table, leaving more food for themselves, according to a linkurl:study published online this week;http://rspb.royalsocietypublishing.org/content/early/2009/06/02/rspb.2009.0544.abstract?sid=004f43ad-84b7-461e-a605-d647c5c15086 in Proceedings of the Royal Society B. Image: Brandon Wheeler"

By | June 3, 2009

Capuchin monkeys cry "predator" to trick more senior members of their troop into fleeing the dinner table, leaving more food for themselves, according to a linkurl:study published online this week;http://rspb.royalsocietypublishing.org/content/early/2009/06/02/rspb.2009.0544.abstract?sid=004f43ad-84b7-461e-a605-d647c5c15086 in Proceedings of the Royal Society B.
Image: Brandon Wheeler
"This is one of the only studies which has actually [used] an experimental paradigm to look at tactical deception," said primatologist linkurl:Katie Slocombe;http://www.york.ac.uk/depts/psych/www/people/biogs/ks553.html of the University of York, UK, who was not involved in the work. In this case, producing false alarm calls allows animals lower in the social hierarchy "to get hold of food that they would not be able to access otherwise." In the forest of Iguazá National Park, Argentina, primatologist linkurl:Brandon Wheeler;http://www.anat.sunysb.edu/IDPAS/index.php?page=students/wheeler of Stony Brook University in New York observed a well-studied population of approximately 25 capuchin monkeys giving "hiccup" calls -- two-syllable cooing sounds commonly uttered in response to danger (play audio for an example) -- outside of their usual predator-alert context. "There [was] no apparent reason to give these calls other than to chase the other individuals off the food platform," Wheeler said. Struck by this curious observation, Wheeler set out to determine if these so-called resource-related deceptive alarm (RRDA) calls were indeed deceptive signals. By placing highly-valued banana pieces on small feeding platforms 3 to 10 meters above the ground, he was not only able to elicit these calls at 10 times the rate they occur in a natural context, he was also able to correlate this behavior with individual rank, food distribution, and proximity to the food resource. With one exception, RRDAs were produced exclusively by subordinate individuals. "There would be no reason for dominants to [call] because they could take the food anyway," Slocombe reasoned. Furthermore, 12 of the 14 individuals observed producing RRDAs were within two meters of a feeding platform, and these calls elicited escape reactions in at least one nearby monkey 40% of the time. The caller was therefore able to feed more freely, either by gaining access to a platform occupied by another animal or by scaring off competitors from the platform on which it was currently feeding. Additionally, the monkeys produced RRDAs more often when the bananas were distributed across just one or two platforms, when competition for access was greater, as compared with three or more. There was no difference in call rate as a result of total food availability, however. Overall, "it does look like tactical deception," Slocombe said. But "we've got no way of knowing whether they actually intend to deceive." The difference between intentional deception and what researchers refer to as "functional deception," Wheeler explained, is whether or not "the individual that's acting deceptively understands that they are creating false belief. If the monkeys are intentionally being deceptive then they understand that they are making the other group members believe there is a predator present." Alternatively, capuchin monkeys may produce RRDAs in response to stress. "Every context that I've seen them give these calls is a context where they can be assumed to be under some degree of stress," Wheeler said. "In the context of feeding, there's lots and lots of aggression." If the stress of a competitive feeding situation elicits RRDAs and these calls successfully scare off other feeding monkeys, individuals may then learn to associate the calls with access to food. In this way, while the calls are indeed deceptive, their behavior "would not be intentional in any sense of the word," Wheeler said. In other words, "deception could be a mere 'spandrel,' a by-product of a signal that is naturally given to a broad range of events," comparative psychologist linkurl:Klaus Zuberbühler;http://psy.st-andrews.ac.uk/people/lect/kz3.shtml of the University of St. Andrews in Scotland wrote in an email. "It forces us to rethink the notion of alarm calls and what might have caused the evolution of these signals."
**__Related stories:__***linkurl:Monkey mugs;http://www.the-scientist.com/news/display/53606/
[21st September 2007]*linkurl:Conveying Ideas or Chattering Idly?;http://www.the-scientist.com/article/display/14884/
[2nd August 2004]*linkurl:Interdisciplinary Study Of Nonhuman Primates Gains Ground;http://www.the-scientist.com/article/display/18029/
[11th May 1998]

Comments

Avatar of: anonymous poster

anonymous poster

Posts: 125

June 3, 2009

Just look how misleading that one named George was!
Avatar of: anonymous poster

anonymous poster

Posts: 11

June 3, 2009

Are dominant monkeys not learning from the repeated deceptions by subordinate ones?
Avatar of: anonymous poster

anonymous poster

Posts: 2

June 3, 2009

I think that for a very long time society has under rated the intellegence of members of other species. I don't believe we clearly thought through survival.
Avatar of: john toeppen

john toeppen

Posts: 52

June 3, 2009

The title of this article does not deserve a question mark. This is a prime example of where we are in arrogant denial regarding the intelligent, clever, mischievous, selfish, and social nature of other species. What would make us think that we are the only creatures that do this sort of thing? We would do well to assume that other creature do these things and see how that model fits the reality. That is, unless that we want to start with the assumption that all creatures were created for human purposes alone, and that we should treat them with disrespect and a calloused disregard until the ?end of days?.
Avatar of: paul harbin

paul harbin

Posts: 1

June 3, 2009

I just think this correlates rather well with, Bush and Cheney. The senior member of the group responding to the false cries of the craftier male. Bush always looked like a buffoon, did he not? Tricky men lie, so do monkeys.
Avatar of: Ruth Rosin

Ruth Rosin

Posts: 117

June 4, 2009

The study only shows that the "alarm call" is sounded also under circumstances where no threatening predator is around. The very label "alarm call" is, therefore misguided, and bound to mislead investigators by sending them in the wrong direction.\n\nWhen the call is made by a monkey that spotted a predator, he himself undoubtedly quickly scampers away, and the others respond in kind, either because they see him running away,or because they quickly scan their environment, and respond by running away , when they spot the predator themselves. \n\nIn the study described here, no threatening predator was involved at all, and the caller himself did not run away. Moreover, the authors state that invariably AT LEAST ONE of the already feeding monkeys ran away; which means that the others did not, either because the caller did not run away, or because they looked around and could spot no predator.\n\nThe only interesting problem the study raises is why do some of the monkeys respond by running away, while others do not, and does the response of individuals change with their experience. This requires studying the ontogeny, (development in the individual organism), of the response to such calls; which requires knowing the previous experience of each individual. And such a study should not even be seriously contemplated by using a wild population, where nothing is known, or can be known, about the previous experience of different individuals. One might even need to study the ontogeny of the preference for bananas, before considering the possibility that the caller made the call with an intention to scare others away, and, thus, gain access to the bananas.\n\nThe idea that if humans deceive, (undoubtedly for very different reasons, in different situations), sub-human animals, (even if they are our closest relatives), must be able to do the same, is a very naive, and misguided approach to the study of animal behavior.\n\nYou can wait from here to eternity, and I bet you will never encounter a monkey typing and sending a comment to The Scientist. Just think of that!
Avatar of: anonymous poster

anonymous poster

Posts: 125

June 4, 2009

"You can wait from here to eternity, and I bet you will never encounter a monkey typing and sending a comment to The Scientist. Just think of that!"\n\nBy a great, rare anomaly, there may just be one that can, down in Dalls, Texas, USA.
Avatar of: john toeppen

john toeppen

Posts: 52

June 4, 2009

Corvidae (crows, magpies, and jays) vocally imitate other animals. I have a recording of a jay imitating a rattle snake (Bird Songs of the SouthWest). They apparently do this to scare coyotes that might otherwise eat them. Tricking others is often a good survival skill. They will also imitate hawks, apparently to provide warnings to other jays. And what are those mocking birds trying to do when they imitate car alarms and cell phone tones?\n\nThese observations might not be the neat repeatable science of controlled populations that we all like to see published. But such real world events are common and reveal social behavior. If we fail to wonder why then we are not doing our jobs as scientists, we might be ignoring the data and not the noise.\n
Avatar of: Ruth Rosin

Ruth Rosin

Posts: 117

June 5, 2009

Where John says that certain birds imitate specific sounds APPARENTLY to scare predators, his use of the term "apparently", means that he is merely conjecturing but has no shred of evidence to support his conjecture. \n\nThis is what scientists should avoid doing!
Avatar of: anonymous poster

anonymous poster

Posts: 1

June 16, 2009

I used to think that mindless nastiness was to be found only in the social sciences/humanities and in the soft sciences. Some of the comments here have totally cleared me of such silly notion.
Avatar of: anonymous poster

anonymous poster

Posts: 3

June 16, 2009

I personally think that monkeys could spell better (even in Dallas) than the anonymous poster of the title "Re: Misleadung terminology"... some monkeys must be smarter than many people! Even if they can't yet type or send letters to The Scientist!
Avatar of: anonymous poster

anonymous poster

Posts: 2

June 16, 2009

It doesn't seem very surprising that monkeys would do this.\nMy dogs discovered this trick a long time ago, although in their old age they are more likely to do it to get more attention from visitors than to get food. They all charge out of the house, then after a few seconds the alarm-sounder quietly sneaks back in to reap the rewards of being the only dog in the house. \n\nBTW: The smallest one totally over-uses the ploy to the extent that nobody believes her alarms any more. When the other dogs are receiving praise, she repeatedly sounds the coyote alarm and charges toward the pet door, looking to see if anyone is following. Nobody is.
Avatar of: anonymous poster

anonymous poster

Posts: 1

June 16, 2009

Sometimes I wonder that more biologists don't simply step back and look around them--like the guy with the dogs. Hopefully this article doesn't shock any animal scientists. Like us, lower animals aren't all-virtuous, and lie to get what they want. I've watched a rooster give the very specific call that means "here's some food" to lure an unsuspecting hen towards him to mate with her (no, it's not a mating call-they'd normally run from his advances--hence the need for trickery). Yes, you want to avoid anthropomorphisms but species snobbery seems just as bad. Why assume that only humans can decieve, or experience sadness or pain, or consider future consequences, or any number of functions that I've heard people say are "uniquely human?" Sometimes the obvious explanation is right.
Avatar of: Ellie Maldonado

Ellie Maldonado

Posts: 5

June 16, 2009

I agree that species snobbery is just as bad as anthropomorphism. For that reason, shouldn't scientists stop using terms that imply judgment of hierarchy, like "lower animals"?

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