Biologists know that calling someone a "birdbrain" is totally unfair. Birds are much smarter than we give them credit for and they're often observed doing some amazing things — like corvids who can retrieve pieces of food tied to string, or woodpeckers who fashion wood scoops out of tree bark to carry honey home to their young.


And as a recent study has shown, the African Grey parrot may be the brainiest of them all — a bird that we know now can make inferences and reason like a three-year-old child.

One of the reasons why birds haven't been given the respect they deserve is by virtue of the fact that their intelligence evolved along a different track from ours and those of other mammals. This has led to a certain kind of negative bias against birds — but it's one that's starting to fade. Studies into the African Grey parrot in particular are showing a high degree of intelligence, including their counting abilities and vocalization skills.


And now, a study conducted by Christian Schloegl and Kurt Kotrschal in Germany is showing that parrots have very sophisticated inferencing skills as well. The researchers were able to demonstrate this by administering a test that had, up until this point, never been tried on birds.


As Stephanie Pappas reports in LiveScience, scientists already know that parrots can make inferences; after being shown two opaque boxes, one full of food and one empty, Grey parrots intuitively know which one has food inside it after the boxes have been closed. Easy peasy.

But Schloegl and Kotrschal wanted to make the task a bit more challenging. Pappas writes:

In their new study, six African Grey parrots were presented with two opaque boxes, one containing walnuts and one empty. Instead of showing the parrots the empty box, however, the researchers shook the boxes so the parrots could hear the walnuts inside. In some cases, the researchers shook either both of the boxes or neither box. In others, they shook just the empty box or just the full one. They found that the parrots could correctly determine that a noisy box was a full box. Even more impressively, when presented with a box that made no sound when shaken, the birds consistently picked the other box, seemingly reasoning that it must be full.


Now this might not sound impressive — but it's important to note that humans are incapable of making this kind of inference until the age of three. Moreover, aside from apes, no other species has been shown to be able to do this — not even monkeys or dogs.

The researchers call this "ape-like cross-modal reasoning" — and their experiment provides evidence that this particular facet of higher intelligence has evolved in animals more than once. The study was published in the Proceedings of the Royal Society.


Top image VogueHouse/Shutterstock.com. Inset image Arbeitsgemeinschaft Papageienschutz.