Researchers find Grey parrots able to use inferential reasoning

Aug 08, 2012 by Bob Yirka report
Timneh African Grey Parrot (Psittacus erithacus timneh) - subspecies of the (Psittacus erithacus). Image: Wikipedia.

(Phys.org) -- A team of German and Austrian researchers has found that Grey parrots are capable of inferential reasoning on a level that is superior to virtually all other animals save great apes and humans. In lab experiments involving choosing which box contains food, the researchers describe, in their paper published in the journal Proceedings of the Royal Society B, how the birds were able to infer through auditory clues, which box contained a hidden food treat.

In this new experiment, the team built on prior research that had shown that when presented with two boxes they couldn’t see through, chose the box with the in it after finding the first empty. Such an experiment showed either that the were avoiding the empty box, or fully believed food was hidden in the second. To get a better reading, they tried a similar experiment using sound instead of sight clues.

In the second experiment, the team showed the birds two opaque boxes, one of which contained food. The researchers then shook the boxes allowing the birds to hear that something was inside just one of them. The birds then guessed correctly which box had the food in it, walked over and tipped it over and ate their treat. Next, however, the researchers tried shaking just the empty box, producing no sound. This time, the birds were able to infer that the food must be in the other box and ran to it when given the chance, accomplishing a feat the team says, humans can’t handle until the age of three. They also say that dogs and monkeys failed when given the same test and that it seems that other than the birds, only great apes and human are known to be capable of such inferential thinking.

To find out just how good the birds were at their inferential thinking, the team resorted to some trickery, they attached tiny speakers to their wrists and played recorded sounds of boxes with food being shaken instead of letting the food make the actual sound. In such cases, they found the birds could not be fooled, they picked the box with food in it only when the sound matched the boxes as they would were they to come naturally.

The researchers also found something else interesting, the birds did better when the boxes were shaken side to side, rather than up and down, likely they say, because the up and down motions of the box distracted the birds because it’s very similar to the way the birds normally bob their heads when interacting with one another.

Explore further: Male monkey filmed caring for dying mate (w/ Video)

More information: Grey parrots use inferential reasoning based on acoustic cues alone, PNAS, Published online before print August 8, 2012, doi: 10.1098/rspb.2012.1292

Abstract
Our ability to make logical inferences is considered as one of the cornerstones of human intelligence, fuelling investigations of reasoning abilities in non-human animals. Yet, the evidence to date is equivocal, with apes as the prime candidates to possess these skills. For instance, in a two-choice task, apes can identify the location of hidden food if it is indicated by a rattling noise caused by the shaking of a baited container. More importantly, they also use the absence of noise during the shaking of the empty container to infer that this container is not baited. However, since the inaugural report of apes solving this task, to the best of our knowledge, no comparable evidence could be found in any other tested species such as monkeys and dogs. Here, we report the first successful and instantaneous solution of the shaking task through logical inference by a non-ape species, the African grey parrot. Surprisingly, the performance of the birds was sensitive to the shaking movement: they were successful with containers shaken horizontally, but not with vertical shaking resembling parrot head-bobbing. Thus, grey parrots seem to possess ape-like cross-modal reasoning skills, but their reliance on these abilities is influenced by low-level interferences.

Related Stories

Crows found able to distinguish between human voices

May 16, 2012

(Phys.org) -- Researchers at the University of Vienna have discovered that carrion crows are able to distinguish between familiar and unknown human voices. They also found, as they write in their paper published ...

Mobs rule for great tit neighbours

Apr 27, 2012

(Phys.org) -- Great tits are more likely to join defensive mobs with birds in nearby nests that are ‘familiar neighbours’ rather than new arrivals, Oxford University research has found.

Quantum Mechanical Con Game

May 05, 2008

For the first time, physicists have come up with a scheme that would allow a quantum mechanical expert to win every time in a con game with a victim who only knows about classical physics. Prior quantum cons have typically ...

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

20 hours ago

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

Apr 17, 2014

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

Apr 17, 2014

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

Apr 17, 2014

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 11

Adjust slider to filter visible comments by rank

Display comments: newest first

Modernmystic
5 / 5 (4) Aug 08, 2012
It certainly diminishes the epithet "bird brain"....
seb
5 / 5 (4) Aug 08, 2012
I for one welcome our new avian overlords!
dnatwork
5 / 5 (2) Aug 08, 2012
They couldn't do a worse job of running the place, that's for sure.
RhabbKnotte
1 / 5 (3) Aug 08, 2012
I am all about animal intelligence and learning that we are not the only creatures able to think. But all we have gleaned here is that auditory stimulation instigates inferential reasoning capabilities. This could be an evolutionarily learned response based on millenia of trial and error. It says nothing about the birds overall inferential skills. I'm not ready to assign them to the top of the evolutionary heap!
TehDog
5 / 5 (5) Aug 08, 2012
I'm not suprised to be honest, http://phys.org/n...096.html
Not to mention Alex the African grey http://www.youtub...Ogs_UlEc
baudrunner
5 / 5 (1) Aug 08, 2012
I think that some birds are smarter than dogs. Crows, for instance.
Ojorf
5 / 5 (1) Aug 09, 2012
Since everyone seems to be thinking, I'll try as well.

I think there are probably plenty more animals capable of complex thought like this, it's just very difficult to prove.
Satene
1 / 5 (3) Aug 09, 2012
It's nice achievement, if we realize, most of PO readers can handle only downvoting and upvoting.
Torbjorn_Larsson_OM
3 / 5 (1) Aug 09, 2012
I know I'm just parroting here, but: good thinking! [/bobs head]

@ RhabbKnotte:

Unique traits are not the same as being special, since there are so many unique traits. I don't think inference is unique, but language and mentor education seems to be unique to later hominins.

The top of the evolutionary heap as measured by population size is viruses, they outnumber bacteria with a factor 10. They have even left genes in our genomes that we have exaptated to protect the human fetus from the female immune system.

I, for one, welcome our viral overlords! ... except when they bring flu.
Deadbolt
3 / 5 (1) Aug 09, 2012
What can humans do that animals can't?

Is language the only thing? Language is what allows us to leverage the intelligence and also knowledge of many brains and allows us to create greater and greater civilization and tech with the passed down knowledge.

However, when we say someone is intelligent, we're talking about them as an individual in terms of effective problem solving.

So, are we really smarter than all animals, or just better at communicating and sharing smartness?
Ojorf
5 / 5 (1) Aug 10, 2012
What can humans do that animals can't?

Probably nothing, it's all a matter of degree. We might be a LOT better than other animals at a bunch of stuff, but nothing that happens in our brains is unique.

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Male monkey filmed caring for dying mate (w/ Video)

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...