About 30 years ago, I gave a talk at the University of California Davis entitled, “Bird Brains Aren’t that Simple.” It was an interesting topic because, at the time, people — and mostly scientists who studied the brain — thought that birds operated at a very simplistic level, and they felt that they were operating on essentially their reflexes only. This was because birds had a smooth surfaced brain, or a lissencephalic brain. The surface of the brain of mammals, including humans, has folds of cortex that are gyri with the invaginations called sulci. This increases the surface area of the cortex and the theory goes that, as you guessed, the animal that had the most gyri would be the most intelligent — us humans! And as the number of gyri decreased, that animal species would be not as intelligent. So when you get to birds and reptiles, the thought was that they must operate on reflexes only, as they have smooth-surfaced brains.
But what if that was not right? What if Bird Brains were not that simple? It seemed that many of the tracts within the brain that takes information to various brain centers and others taking information down the spinal cord to the peripheral nerves were similar between mammals and birds. And the brainstem of birds was like mammals. There were also many corollaries except for that smooth outer surface of bird brains that seemed to get in the way of human thinking. Slowly there were other neuro scientists who were beginning to think that birds were — well, intelligent. How could they do this and why did some evolve to be more intelligent than we humans thought?
The Crow Knows
The intelligence of the corvid family — a group of birds that includes crows, ravens, magpies, rooks and jackdaws — rivals that of apes and dolphins. Parrots are also in this mix of intelligent birds. It is just that more studies have used crows as their model. Recent studies reveal impressive details about crows’ social reasoning, offering hints about how they developed interpersonal intelligence even as we humans evolved similar types of intelligence. While the brain structures may vary in form, crows developed the capacity to solve not just physical problems, but to process and use social information.
For example, if you are a food-storing corvid, the social context of caching stores of food is important, as caches are vulnerable to pilfering from other crows that are watching. The ability to observe conspecifics of their own kind and remember what, where, and even when the food was stored is valuable information in coming back and successfully pilfering that store.
A clever crow may use counterstrategies to lower the risk of cache pilfering, which may depend on cognitive processes. For example, it could hide food behind barriers to block the view, or make a cache of a non-food item. Perhaps a more clever crow would return to caches made while conspecifics looked on and then recache the food in a new place! This would correspond to “bait and switch” deception in the human world. The bird’s ability to recache these stores depended on an awareness of what the other birds were seeing and were likely to do, and then developing a strategy to deal with that threat.
Interestingly, it seems that corvids could distinguish that there was no need to recache if their actions had not been observed by conspecifics. This mix of prospection and retrospection in regard to what potential plundering conspecifics could have seen is remarkable. This mental feat rivals that of nonhuman primates. This suggests that many birds that cache food must remember the what, where and when of these specific caching events — that requires episodic memory for success.
Additionally, those species that store food must be sensitive to the social context of caching. This may also occur with parrots that need to find food in a vast tropical forest with the social context of a flock. The more social interaction within the flock, the greater the intelligence to deal with its flock mates. Comparative studies of caching in different species of birds suggest different levels of adaptive social learning.
Cognitive Tools Of Birds
Nathan NJ and Clayton NS proposed that cognition of crows is similar to the cognition of great apes. Their theory of evolution of similar cognitive abilities was based on the fact that these species face similar socioecological challenges that include locating perishable food distributed in time and space or understanding the relationships between different individuals within large social groups. This required that these problems were solved using 4 cognitive tools that have driven complex cognition from birds to primates. These 4 components of the cognitive tool kit are: causal reasoning, flexibility, imagination and prospection.
Bird owners have remarked and made videos of their birds as they take objects and manipulate them to cause another effect — like getting to the food inside the toy. This use of enrichment is a form of causal reasoning, and we see that our large flock parrots like cockatoos are better at figuring out these more complex tasks to get to the food.
The ability to act on information with flexibility is considered a cornerstone of intelligent behavior. Flexible learning strategies form the basis of creativity. Birds like crows that cache food at various temperatures and retrieve those items relating to decay rates of various food items have great flexibility. This also relates to those birds that are able to take a general rule and generalize them to solve a unique problem. Jays, for example, are very good at using concepts and then applying them to novel situations in the research lab as well as out in the wild.
The ability to form representations of objects outside of perception or object permanence is considered a precursor to imagination. The work of Dr. Irene Pepperberg with Alex the African grey suggests that this occurs in birds as well. She describes how Alex understood the concept of zero, or nothing, just before he passed away.
The ability to imagine future events is the concept of prospection. Caching is an act of future planning. Recaching only when conspecifics noticed the caching and its site is an act of prospection for pilfering of caches.
While there is convergent evolution of cognition, there is not convergent evolution of the structure of the brain. There are parts of the brain that is the same from a structural and functional point of view between birds and primates. But that old smooth surfaced cortex figured out the concept of zero in Alex without the use of gyri and sulci! And we humans should never think that certain bird species like our parrots can’t anymore.