Rather widespread in France and well known for the beautiful bright colors which adorn its variegated plumage, the oak jay (Garrulus glandarius) is a large passerine bird that is part of the corvid family. It has several surprising features. For example, it is quite talkative and can utter unpleasant hoarse cries when it feels in danger, thus acting as a real forest sentinel for all the animals around it. During the mating season, these very recognizable calls transform into more melodious clucks. It also has a certain talent for imitating the cries of other birds (such as the common buzzard) or even mammals such as cats to intimidate possible predators. His talents, however, are not limited to screaming and singing. A new study has just revealed another exciting ability of this incredible bird.
Episodic memory does not only exist in humans
Humans are capable of mental time travel, a capacity called chronesthesia directly linked to episodic memory. When they remember past events or experiences, it allows them to remember details that may have seemed unimportant at the time. “ When we remember a specific experience, we may remember details of that experience that were unimportant to our needs, thoughts, or desires at the time. These “accessory” information are nevertheless automatically encoded as part of the memory and are then recalled when we remember a moment », explain the researchers.
Science has long believed that only humans possess this talent. However, studies have over time qualified this vision, demonstrating that rats and other animals also had episodic memory on their scale. This new work published on May 15, 2024 in the journal Plos One and carried out by the University of Cambridge (England) provides further proof, this time in the oak jay.
Equipped with a hard and powerful beak which allows it to feed on the acorns it is fond of, this animal prepares generous, well-hidden reserves, so much so that it ends up not being able to eat everything. The remaining acorns will then germinate and help the oak prosper with new growth. The team was therefore particularly intrigued by the fact that these birds know how to remember their hiding places very precisely of food, suggesting that they have evolved to develop good episodic memory. To investigate the subject a little further and better understand the memorization abilities of this bird known for its great intelligence, the researchers gave it tests.
A bird with real memorization skills
For these experiments, the birds could see food (worms) being placed under a container placed in a line with three other identical red cups. They were then rewarded when they managed to find the correct container. The researchers quickly succeeded in training them to identify the container simply by memorizing its position on the line.
The team then decided to make the task more complex without preparing the birds. In the second part of the experiment, the reward was this time placed under cups which all presented clearly visible visual characteristics allowing them to be differentiated. After observing the cup under which the worms were placed, the jays were separated in another room for about ten minutes, while the scientists mixed the cups. Despite the wait and the rearrangement of the containersreturning to the room, the birds were able in 70% of cases to find the right cup just based on the details present on its surface.
What do these tests tell us about this bird?
These observations are significant since the birds had only been trained to spatially find the reward, without focusing on the container itself. During the second test, they therefore did not have no particular reason to remember the shapes on the containers used, something they were nevertheless able to do. “ As the jays were able to remember details that had no specific value or relevance at the time the memory was created, this suggests that they are able to record, remember and access non-primary information when they try to remember them », conclude the researchers. This demonstrates that they are also capable of chronesthesia.
However, the team insists that “ Although this study provides compelling evidence suggesting that oak jays can encode, retain, and access innocuous visual information, this ability may be limited to information associated with the food cache and is not perhaps not as flexible as human episodic memory is “. Additional tests will therefore be necessary to determine whether this bird can use its memory for anything other than food.
In any case, this remains further proof that animals are capable of intelligence and are blessed with fascinating abilities once thought unique to humans.
