What do great apes, pigeons and parrots have in common? You might not think much at first glance, but they do have one important thing in common: they can rank. And we didn’t know that about those parrots yet.

Classification means that animals – or humans, if you will – can distinguish between two objects: for example, they always know how to point to oranges when they have to choose between oranges and bananas. In this case, kea, a New Zealand parrot species, was able to choose from two images a picture of the face they or they did not know. A skill that has so far only been seen in very few animal species. Austrian researcher Elisabeth Sovandchev explains in an interview with: Saintias.

take a picture
world University of Veterinary Medicine Vienna tells how search He went about his work: “For this experiment, we trained twelve kea parrots to click on one of two pictures shown on a touch screen with their beak. For each correct answer, they were given a peanut. Pictures of the subjects were taken from different angles, sometimes From above, sometimes from the side. One photo has always been of a person with whom he has been in close contact for the past five years, while the other is of a completely unknown person.” Half of the animals were rewarded for choosing a known person and the other half for choosing an unknown person. Both groups may have used the famous person as the deciding factor.

The control group also had an important task this time around. “They were shown the same pictures of human faces and rewarded for choosing certain pictures.” However, it wasn’t about known vs. unknown people, but rather about a mixture of the two. “So it was impossible for the control group to apply the concept of familiarity to choosing between the faces they saw.”

More and more pictures
But the experiment did not end there. By adding more and more pictures of new people, known and unknown to the test, we were able to see if the test group was able to apply this concept. And guess what: This group was indeed faster at solving the task if more pictures were added. This indicates showed that the parrots were able to use the concept of familiar versus unfamiliar faces.The test group could immediately make the correct decision, because they could immediately associate the new images with familiar versus unfamiliar faces.The control group again had to learn the new individuals specifically , but significantly: in the second session, these birds were also able to choose the appropriate pictures, which indicates that the control group already understood the task so well that it was enough to see the pictures once.

Same test, different reward
“We did the same thing in the last test: we added a number of new pictures and the parrots had to distinguish between familiar and unfamiliar faces,” adds researcher Raoul Schwing from the University of Vienna. “Everything remained the same for the control group, but we changed the reward for the test group. If half were rewarded first for choosing the unfamiliar face, they now got a reward for correctly choosing the familiar face. And vice versa for the other half. Not many birds were able to They understood this, but some could. And that’s very clever, because most animals in general are unable to apply more than one rule at a time. The parrots succeeded: for the new pictures they were shown, they applied the new rule—they were rewarded for choosing the known picture— And for old photos they applied the old rule – they chose the unknown photo.”

It was not easy for the parrots. To ensure that the images were as similar as possible, all subjects had a white sheet around their neck and torso. They were also asked to appear neutral. This was so that the kea could not use other signals to complete its task, such as an inscription on a shirt. They only had facial information to make their decision, Suwandschieff said.

Handsome heads
The fact that parrots managed to do this is quite an achievement. This means that of all the cues that animals use to discriminate between individuals, facial information alone is sufficient. Thus they can use this concept of familiarity to solve a task where there are two classes. This puts parrots in the same league as the great apes and pigeons who have already proven they can do this. “Parrots show that they are capable of the same things as our closest relatives. This is remarkable given the genetic distance between the two animal species,” he says admiringly.

Free as a bird
Finally, there is also a practical application for the animals themselves. The results show that parrots in the laboratory can adapt flexibly to their environment, developing the ability to distinguish between humans. A skill that was never needed and therefore never evolved in the wild. On the other hand, this ability also has implications for the welfare of the animals, and therefore must be taken into account when handling and breeding parrots,” explains Suwandschieff. The parrots were not caged in the laboratory during the experiment, but they were able to fly freely in a cage of more than 500 square meters.

But why did the researchers actually choose the kea parrots? “They are very exceptional birds. They have complex social structures, are opportunistic foragers, and are very fond of new things. All of these characteristics make them a very suitable species for testing flexible behavior, technical and social intelligence, and problem-solving ability.”

do not confess
The researchers want to stress that they haven’t investigated whether animals actually recognize people they identify as a single caretaker, for example. They only tested whether or not the animals were able to distinguish between familiar and unfamiliar faces. “We are basically testing the parrots’ ability to categorize at a higher level. The fact that we used pictures of known and unknown people is not really the most important thing. We could also use pictures of different fruits in yellow or orange,” said researcher Raoul Schwing.

He explains, “Our selection of facial images made it more complicated. We showed that parrots are able to synthesize different images of the same person.” So the animals can match pictures taken from different angles of the same person. But we have to be careful when we talk about confession. They recognized familiar faces, but that’s not technically what we’re shown. What we’ve shown is that they can use pictures of familiar faces as a way to classify them. However, we see evidence in the way the body interacted with certain people and responded to those who approached them that they identified with different people.”

Fast learner
“But the fact that the animals were able to classify is really cool,” says Suwandschieff. And the final test was, of course, very special: the animals had to understand that it wasn’t the choice of the familiar face that resulted in the peanut, but the unknown image. Animals can apply the same concept, with the reward reversed. It was very surprising that this worked, especially considering how quickly the kea parrots learned the trick.”

Now that the parrots have shown what they can do, the researchers want to do more testing. “It’s really interesting to see if animals recognize people. This requires a different test setup with multiple stimuli, such as pictures of people combined with their voices. But now I’m researching kea social learning skills, which is another great research area. Ultimately, We still know very little about many species, so there’s still a lot to research.”