Sometimes it is known that waiting wisely is the order of the day: people can resist immediate temptation if they know that it will reward them later. Parrots are also capable of this so-called impulse control, a modified version of the marshmallow test now documents. How well the clever birds can control themselves depends on the type of bird and the ability to distract themselves while waiting. The African gray parrots were the most disciplined, report the cognitive researchers.
As early as the early 1970s, the famous marshmallow test made it clear that people can be disciplined from childhood. Four-year-old children were each given a single piece of the candy and said: “You can eat this one marshmallow now – but if you wait a little longer you will get two”. It was shown that the young test subjects are capable of impulse control, and also how individually the willingness to delay reward can turn out to be. This ability was initially considered to be typically human, because animals hardly seemed to be able to withstand a direct feed stimulus. However, exceptions are now known: some particularly intelligent animal species are also capable of disciplined intellectual performance, studies show.
In the current study, the researchers led by Auguste von Bayern from the Max Planck Institute for Ornithology in Seewiesen (MPIO) have further explored the ability to control impulses in parrots. One question was to what extent there are species-dependent differences in the representatives of this intelligent group of birds. The researchers therefore compared the performance of three species from America and one from Africa: six blue-throated macaws, eight great soldier macaws, six blue-headed macaws and eight African gray parrots took part in the tests.
Walnut instead of marshmallow test
In order to record the ability to self-control, a concept was used that corresponds in its principle to the marshmallow test. The birds were offered sunflower seeds – a moderately popular food – on a spoon through a small opening in a window. During the experiment, however, the birds could see through the transparent window that there was a chance for even more attractive delicacies: walnuts. They finally learned that after a certain period of time, the device would continue to rotate and instead of sunflower seeds, it would bring a delicious walnut within reach. In doing so, the birds apparently got the catch: if they got down to the sunflower seeds, the turntable stopped immediately and there was no walnut.
As the researchers report, eventually all feathered subjects were able to resist consuming the moderately attractive food within a certain time frame in order to wait for the preferred food. Test runs with different waiting times showed, however, that there were clear differences in the animals’ patience: The scientists found that the African gray parrots could wait on average just under 30 seconds for their preferred food, compared to 20 seconds for the large soldier macaws, 12 Seconds for blue-headed macaws and only 8 seconds for blue-throated macaws. There was also a considerable range of patience within the species: the best performance was achieved by a gray parrot named Sensei – it could wait up to 50 seconds.
Species-dependent patience and coping behavior
During the experiments, the researchers also observed an interesting behavior that was also observed in a similar form in humans or, for example, dogs: while the birds were waiting for the walnuts, they showed coping or distracting behavior. “We suspect that this is how the birds suppress the impulse to eat the food they do not prefer. This enables them to cope better with the wait for the food they prefer, ”explains Auguste von Bayern. The respective behaviors varied depending on the bird species: the African gray parrots paced up and down in front of the window, while the macaw species nibbled at seed pods or tampered with other objects. The more time a bird spent with these distracting behaviors, the more successful it was while waiting, the scientists report.
“Overall, our results suggest that self-control skills vary widely between species and individual individuals,” says lead author Matthew Petelle. “We suspect that this is related to differences in relative brain size or general intelligence.” There is also evidence that the diet or the social organization of the various species may have an influence. The researchers suspect that self-control may be more pronounced in bird species that have to invest more time in their foraging or that live in a more complex social environment.
But as far as this is concerned, there is now a need for further investigation. Because so far little is known about how the parrot species studied interact with their natural environment and other parrots in the wild, the researchers emphasize. Future studies of social behavior, foraging, and brain size may shed more light on the influence of these factors on self-control in parrots.
Source: Max Planck Institute for Ornithology, specialist article: Animal Cognition, doi: 10.1007 / s10071-021-01565-6