In our recent podcast episode "The Unsettling Depths of Bird Intelligence," Robert and I discussed the mounting evidence that birds -- especially parrots and corvids -- are much smarter than previously thought. In some cases, they appear to display intelligent behavior so sophisticated that it's a little unnerving.
The episode was inspired by a recent review in Trends in Cognitive Sciences called "Cognition without Cortex," by Onur Güntürkün and Thomas Bugnyar. We contacted Dr. Güntürkün over email to ask him some follow-up questions from our research into the subject, and he generously shared his thoughts. Below is the full text of our interview.
Stuff to Blow Your Mind: What first got you interested in the subject of avian cognition?
Onur Güntürkün: I grew up in a pigeon lab and for me it was always given that birds can be pretty smart. Only in the late phase of my PhD I realized with astonishment that the absolute majority of scientists thought that birds are just beautiful reflex machines, devoid of any higher cognition. In interaction with scientists that were highly skeptical about avian cognition, I realized how much of an uphill battle it is to convince people that birds can show cognitive properties identical to mammals.
STBYM: How much difference is there between cognition in bird species? We're now learning how intelligent corvids and parrots are, but are the chicken and the pigeon probably much smarter than we thought as well?
OG: It doesn't make much sense to talk about birds and mammals in general. It is much more useful to compare some groups of birds with some groups of mammals. There is practically no important difference in any cognitive repertoire between corvids and parrots on one side and primates on the other side.
Obviously it would be a bit unfair to compare a chicken and a pigeon with an ape. But this is also true for mice and rats. So, to put it in a bit unscientific way, chickens and pigeons are possibly comparable in many aspects with rats when it comes to cognition. That said, it is important to state that the cognitive differences between rats and monkeys on the one side and pigeons and corvids on the other side are often overestimated. Careful observations show that chickens and pigeons (as also rats) achieve a much higher level of cognitive operations than often assumed.
STBYM: In your personal opinion, what's the single most startling or impressive display of sophisticated cognition you've ever seen in bird behavior?
OG: Imagine you are sitting in front of a rich table full of tasty food and you are asked which of the many items on this table is the most delicious one. That's my situation now. But if you force me to give an answer I would like to mention two points. The first is self recognition in the mirror, as shown by magpies. This finding possibly implies that magpies know about themselves. And they share this kind of knowledge with chimpanzees and a few other ape species. The second aspect that I find fascinating is social cognition. Corvids seem to know in some detail what other animals can know and what they can't know. They also seem to have a certain understanding of the intentions of other corvids and they possibly are able to at least anticipate how another bird is feeling in a certain situation. Just a few years ago, nobody would have thought that this was within the reach of a bird.
STBYM: You write in "Cognition without Cortex" that you don't think complex avian behavior can be explained by instincts in a narrow range of areas that are strongly genetically determined (for example, food hoarding). In other words, the smart stuff we see birds doing can't just be hard-wired; it has to be adaptable thinking. Why do you think flexible cognition is a better explanation for the behaviors we see?
OG: The critical task of an experiment in cognition research is to construct an experiment in which the animal is suddenly faced with a novel problem. The animal can either respond with a routine behavior that would not provide a proper solution, or it could respond with something completely new, never done before, that then results in success. If the animals would be purely instinct driven they would respond with routine behavior. If they are cognitively able to understand the whole situation, then they should be flexible in their responses. This is exactly what we observed in many corvids and parrots.
STBYM: Do you think there's compelling evidence that birds are capable of mental time travel (i.e., cognitive awareness of the past and the future)? We see split opinions about this, with the main avian candidates being certain ant-hunting tropical birds and scrub jays.
OG: I personally believe that at least some bird species are capable of mental time travel. In fact it seems to be that as soon as birds are able to fulfill the criteria for mental time travel, the criteria are shifted until they end up in requirements like consciousness - something that is extremely difficult to prove in a non-human animal. I have no problem with the fact that not all bird species are able to show mental time travel.
STBYM: Can you explain in non-expert terms what a connectome is, and how the bird connectome helps us understand the neurobiological basis of avian cognition?
OG: Even simple brains have hundreds of millions of connections between their neurons. Is there any hope to understand the general properties of information flow within even such simple brains? Can connectome analysis give us at least some answers for this? Using mathematical analysis it is possible to understand some principle organizational features of brains. We can see for example that certain areas of the brain create modules in which dozens of small areas are tightly interconnected and seem to be cooperating on a certain process. We also see that some areas are hubs that work like international airports.
Suppose you would like to fly from Cordoba in Spain to Fairbanks in Alaska. You should take a plane from Cordoba to Madrid and then from Madrid to Seattle and then from Seattle to Fairbanks. Madrid and Seattle are international hub airports. Flights from all over the world come there and are then dispatched to many smaller destinations. In the connectome we can see that some areas in the brain serve as hubs. Some other areas are like smaller local destinations. Possibly the connection of the major hubs of the brain within each other constitute the backbone of major cognitive processes in the brain.
These are just a few examples of information that you can extract from connectome analysis. Astonishingly, the connectome of the pigeon brain turns out to be quite similar to the connectome of the cat, the monkey, and the human brain. It seems that there are not many ways to construct a blueprint for brains that have to serve complex cognitive properties. Therefore, evolution always converged onto similar solutions even in very distantly related animals.
STBYM: What can studying the brains of birds teach us about the relationship between neuroanatomy and intelligence more generally? For example, if we see these examples of sophisticated cognition in animals with just a few grams of brain matter, does it do anything to challenge the common assumption that an animal's intelligence will usually be correlated with brain mass or brain case volume?
OG: I see two very general lessons.
First, many of the features that we have discovered in the human brain especially and in the mammalian brain in general are not specific to mammals. We thought that they were sort of a condicio sine qua non for a mammalian-type higher cognitive ability. They are not. They are equally shared by birds. Thus, we are not alone and these feathered animals are much more like us than we previously thought.
Second, we were absolutely sure that brain size was a strong predictor for cognitive excellence. We were wrong; at least partly. It is true that within mammals, bigger brains -- or, to be more specific, brains with more neurons -- correlate with higher cognitive abilities. The same is true for birds where parrots and corvids have bigger brains with much more neurons than, say, chickens and pigeons. But if you compare birds with mammals, then you see that parrots and corvids churn out the same cognitive abilities with much smaller brains that primates do. Thus, birds somehow found a way to come up with much more mental power with smaller brains than we mammals are able to do. It will be fascinating to find out how they do that.
STBYM: A bit of fantastical speculation: If evolution had gone a different way, could avians (rather than primates) have become the dominant intelligence on planet Earth, even developing a technological civilization? What might that look like?
OG: In principle, yes. However, birds have a problem that all reptiles have. They are unable to construct big brains. This could be related to the fact that in reptile brains (and so also in bird brains) the forebrain is not divided into grey matter and white matter. In mammals this division is very important and the mammalian cortex can grow like a folded carpet theoretically endlessly. In the reptile/bird brain the upper limit seems to be reached by a little more than a hundred grams. We haven't understood this point completely yet, but to be as smart as we humans are, birds possibly would need a couple of hundred grams. And as long as they are unable to come up with that, we rule this planet.
Onur Güntürkün is a biopsychologist with Ruhr-University Bochum. You can find more of his work at the RUB Department of Biopsychology homepage.