Sometimes it’s a good idea to wait wisely: people can resist immediate temptation knowing it will reward them later. Parrots are also capable of this so-called impulse control, a modified version of the marshmallow test is now documented. How well the clever birds can control themselves depends on the bird species and the ability to distract themselves while waiting. The African gray parrots proved to be the most disciplined, the cognition researchers report.
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 have two”. It was shown that the young subjects are capable of impulse control, and also how individually different the willingness to delay rewards can be. This ability was initially considered to be typically human, since animals hardly seemed able to resist an immediate food stimulus. However, exceptions are now known: Studies show that some particularly intelligent animal species are also capable of disciplined intellectual performance.
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 of parrots to control impulses. One question was to what extent there are species-dependent differences among 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 green macaws, six blue-headed macaws and eight African gray parrots took part in the tests.
Walnut instead of marshmallow test
A concept similar to the marshmallow test was used to measure self-control skills. Sunflower seeds – a moderately popular food – were offered to the birds 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 an even more attractive treat: walnuts. They finally learned that after a certain time the machine keeps turning and instead of the sunflower seeds, it brings a delicious walnut within reach. The birds apparently also understood the problem: when they attacked the sunflower seeds, the turntable stopped immediately and there were no walnuts.
Eventually, the researchers report, all feathered subjects were able to resist consumption of the moderately attractive food for a period of time in order to wait for the preferred food. However, test runs with different waiting times showed 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 great green macaws, 12 seconds for blue-headed macaws and only 8 seconds for blue-throated macaws. There was also a wide range of patience within species: the best performance was achieved by a gray parrot named Sensei – it could wait for 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 distraction behavior. “We suspect that the birds thereby suppress the impulse to eat the food they do not prefer. In this way, they can better cope with waiting for their preferred food,” explains Auguste von Bayern. The respective behavior varied depending on the bird species: the gray parrots paced up and down in front of the window, while the macaw species nibbled at seed pods lying around or tampered with other objects. The more time a bird spent engaging in these distracting behaviors, the more successful it was at waiting, the researchers report.
“Overall, our results indicate that self-control abilities vary greatly between species and between individuals,” says lead author Matthew Petelle. “We suspect that this is related to differences in relative brain size or overall intelligence.” There is also evidence that the diet or the social organization of the different species could have an influence. The researchers suggest that self-control may be more pronounced in bird species that spend more time searching for food or that live in more complex social environments.
However, there is now a need for further investigation in this regard. Because so far, little is known about how the studied parrot species interact with their natural environment and other parrots in the wild, the researchers emphasize. Future studies of social behavior, foraging, and brain size may thus shed more light on the impact 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