Among birds, it was also out of ease that behaviorists essentially chose pigeons to study learning and categorization. These researchers had tried some studies on crows, but these proved to be too annoying, preferring to dismantle the operating conditioning apparatus than to lend themselves to the planned tests.
This view of birds began to change thanks to Irene Pepperberg and her famous African grey parrot named Alex.
Pepperberg began training this parrot as early as 1977 and has shown that it is able to use human language with impressive results (Pepperberg, 2006).
When Alex died in 2007, at the age of 31, he could not only name, in English, about fifty objects, but he could also, for the same object, answer the questions “What shape?”, “What color?”, or “What matter?”.
It could also combine two properties to answer questions such as “In what matter is the object that has 4 corners?” or “What color is the smallest object?” and even answer the question “what is the same?” or “what is different?” indicating whether it was the shape, color or material of the objects presented.
He also knew how to count to 8 and make additions say “no” when he didn’t want something, and express desires like: “I want this thing” or “I want to go to this place”.
Alex’s performances are therefore comparable, by the level of abstraction achieved, to those of great apes trained to communicate with humans.
The end of the twentieth century saw the rise of the social brain hypothesis. This hypothesis suggests that it would be in response to the complexity of their social environment that cognitive processes would have developed particularly in primates, including humans (Dunbar, 1998).
This hypothesis has given rise to a great deal of research on primates that has shown the extent and complexity of cognition in these animals.
However, primates have no monopoly on social life or intelligence. Some birds live in social groups in which they maintain networks of complex and diverse relationships.
Emery and Clayton suggest that divergent neuroanatomical evolutionary mechanisms have led to convergent cognitive abilities in some birds and primates, at least in the social domain (Emery & Clayton, 2004).
In these two groups, which Emery calls the “feathered great apes”, birds have large brains relative to their size (particularly with regard to the anterior part of the brain, equivalent to the prefrontal cortex of mammals), and have a complex social life, with long childhood and an equally long lifespan (up to 50 years for ravens, 80 years for macaws…).
More and more researchers then became interested in the cognitive abilities of corvids and Psittacidae, especially in the social field.
Can crows talk
Crows that talk
These little-known and little-appreciated birds because of their gloomy appearance are nevertheless very intelligent. In captivity, some species of crows can learn to talk and imitate sounds, and they prove to be better than most parrots.
In the wild, this technique is useful for them to feed themselves: they imitate the cries of wolves and foxes to attract them to animal carcasses too robust for their small beaks.
After the satiated canids with sharp fangs, they can thus feed on the remains that are accessible to them. The carrion crow, which looks a lot like it, is considered by specialists to be the most intelligent bird.
She is more resourceful than most primates, including great apes. From the age of six months, she has skills equal to a 5-year-old child.
Ravens can talk!
SOURCE: Talons and Teeth
Fry crows form alliances: allies share their food, groom each other and help each other during aggression. The birds know the relationships maintained by the other members of the group since there are cases of redirection of aggression: the animals attacked or their allies take revenge against the attacker’s allies.
Knowledge of hierarchical relationships was tested in pine forest jays. During the experiment, a bird, called an observer, witnesses an interaction between congeners in which it sees a bird hitherto unknown to it to be dominant compared to a third congener, known to the observer.
This congener belongs to the same group as the observer and is dominant in relation to him. The observer and the unknown bird are then placed in the same cage.
The transitivity relationship makes it possible to infer that this unknown having gained the interaction against a dominant jay in relation to the observer, would logically also carry the interaction against the observer.
The researchers found that the observer bird is indeed submissive when it is put in the presence of the unknown bird (which is not the case when the observer bird does not benefit from the same information).
Jays are therefore able not only to form categories of relations as dominant and subordinate but also to use a transitivity relationship to deduce relative dominance.
Theory of mind
Theory of mind is used to describe the ability to attribute mental states such as perceptions, intentions, knowledge, or beliefs to others. This ability could allow animals to predict and manipulate the behavior of their congeners.
The theory of mind probably includes different levels requiring more or less advanced cognitive abilities and is the subject of much debate within the scientific community.
In the laboratory, or in nature, ravens, and jays that hide food by burying it do so preferably behind a screen rather than being visible to a congener so that the latter cannot know where the food is hidden.
Parrot African Grey also prefers to steal forbidden objects (such as pens or erasers) by hiding behind a screen so as not to be seen by the experimenter.
The Congo Grey Parrot can also decipher the apparent intentions of an experimenter: to verify this, the bird is placed in front of a researcher who gives it sunflower seeds through a fence.
In some cases, the researcher seems to try to give him the seeds without being able to get them through the fence, in others he obviously does not want to give them to him.
Parrots react differently under these two conditions, identical in that the parrot does not receive the seeds, but different in terms of the apparent intentions of the researcher:
the birds bite the fence (the apparent obstacle) when the experimenter seems to be of goodwill, while they address the researcher who does not want to give them the seeds by opening the beak, emitting request vocalizations, or by hitting the table with their beak, a sign of frustration.
These birds do not react in the same way depending on whether the person facing them seems to have good or bad intentions…
Other experiments give even more impressive results: white-throated jays first have the opportunity to observe congeners hiding food.
The subjects are then divided into two groups: one of these groups (jays called “thieves”) can plunder the caches of the observed congeners, while the other (so-called “honest” jays) is prevented from doing so.
In the testing phase, all are given food and have sand-filled ice cube trays at their disposal to allow them to hide food; some are observed by other jays while they hide, while others are alone. Three hours later, the observer jays are removed and the subjects are given a new sandbox.
It is observed that the “stealing” birds, having already looted the caches of others, will be suspicious and spit their food in the new tank if they have been observed during their first cache, while among the jays of the other group, “honest” since they have never had the opportunity to plunder the caches of others, very few buy their food.
It would therefore seem here that the jays “thieves” attribute to their congeners both an intention (they will plunder the hidden food) and a knowledge (they know where it is when they were present at the time when it was hidden).
Their behavior is not purely instinctive since only jays who have themselves had the opportunity to steal are suspicious of others.
Crows that talk
Self-recognition in a mirror is probably related to self-awareness that would facilitate the theory of mind (since being aware of one’s own states would allow one to better represent those of others).
Self-recognition is demonstrated by the famous stain test (see the article “Fish, the mirror and self-awareness” in the journal n° 99):
a spot is placed on a part of the body invisible by the animal (on the forehead for example); if he touches this spot only after having access to a mirror, it can be deduced that he knows that it is his reflection that he sees.
Only a few animal species have shown recognition in the mirror: anthropoid monkeys, dolphins, elephants, but also magpies.
Innovation and use of tools
In birds, the rate of innovation (measured by the appearance of new behaviors in wild birds), as well as that of tool use, is correlated with the relative size of the forebrain.
Unsurprisingly, therefore, a particularly high rate of innovation is observed among corvids. Some crows use tools flexibly. Thus, the crows of New Caledonia use two types of tools to recover insect larvae under the bark of trees:
- square brackets.
- cut leaves.
The sheets can be cut to give wide or narrow tools, or wide at one end and narrow at the other end, with a staircase shape between the two ends, which requires several manufacturing steps.
Crows use different tools in different areas.
From the distribution of these tools according to the zones, it seems that we are facing a case of cumulative evolution: in some places, crows make simple tools in a single step, further, they make more complicated and effective tools in two stages, further still in three stages.
The more complex tools, therefore, seem to have been invented from simple tools, from time to time a crow would have made an improvement and then would have been imitated by others.
This idea of cumulative evolution is of great interest to researchers because this is how human technology appeared.
In the laboratory, these birds can choose from several tools whose size or shape is most suitable for getting food out of a tube.
The researchers also tested a pair of this species to see if the birds would be able to choose between two wires, one straight and the other curved, more efficient at extracting food from a tube.
The male has taken the curved wire, and the female, Betty, spontaneously twisted the straight wire that remained at her disposal in order to give it the appropriate shape.
She later repeated this feat in 9 out of 10 trials. Betty had had experience with curved tools, but not how to make them; his technique of bending iron wires was different from those used by his congeners in nature.
So Betty invented a new technique, without resorting to learning by trial and error. Such a deliberate modification of a tool, without prior demonstration and intensive training, is very rare even in monkeys.
A musical sensibility?
Animals can also share some aspects of our own culture: parrots raised in the homes of their owners and thus put in contact with songs or music can enjoy singing certain opera arias or dancing, spontaneously showing a sense of rhythm very rare in non-human animals!
In Australian black cockatoos, males make a tool using a branch and then use it to drum on hollow tree trunks, each male has its own rhythm.
In our laboratory, African Grey Parrot and cockatiel parakeets learned how to use a touch screen to listen to music; birds thus having the choice between different pieces of music showed stable individual preferences,
some preferring music with a fast tempo, others choosing quieter music. We also found more closeness between individuals and less aggression when music is played.
Cooperation and empathy
We also tested three Congo African Grey Parrot in a cooperation task in which two birds had to pull at the same time on both ends of a string, the latter sliding through rings fixed on a tray, to bring closer to them this tray containing food and initially placed out of their reach.
Once this task was understood, we gave them the choice between two devices: one (duo device) requiring the cooperation of two individuals as described above and the other (solo device) comprising a string whose two ends were knotted and thus allowing a single individual to advance the plateau.
However, the two devices were not equivalent in the amount of food: the duo device included four times more food than the solo device.
We then observed choices that varied according to the individuals: the female, Zoé, chose the solo device when she was alone (logical since she could not have operated the duo device alone) and the duo device when she was tested with Leo, another parrot with which she had been raised:
logical again since she thus obtained more food. But when the only congener present was Shango, another male often aggressive with her, she would again choose the solo device, giving up part of the reward to avoid cooperating with Shango.
When the same choice was offered to Shango, he systematically went to the solo device (whether a congener was present or not), preferring to depend only on himself, even if it meant receiving less food.
As for Leo, a bird of affable character and getting along well with Zoe as with Shango, he chose the duo device regardless of the partner present, thus maximizing the amount of food obtained.
Thus our three birds, although all trained in the same way, showed different strategies, adapted to their own temperament but also to their relationships with others…
Parrots also show empathy. In wavy parakeets as in humans, yawning is contagious, while cockatiel parakeets are stressed when they hear the alarm calls of their congeners, and even more stressed if they are congeners with whom they have a special affinity.
We also observe in wavy parakeets, as well as in several species of corvids (ravens, fry crows, jackdaws) behaviors that can be called “consolation”: birds that have just been engaged in a conflict receive from a bird not involved in this conflict (often their partner) affiliative behaviors such as grooming.
We have barely skimmed in this article a part of the experiments, more and more numerous, showing the extent and richness of the abilities of parrots and corvids.
These birds are intelligent, feel emotions, play (Emery & Clayton, 2014), bond with their peers or humans, and need to express their natural beha