Unique Brain Circuitry Might Explain Why Parrots Are So Smart

Their bird brains are not bird-brained

An African grey parrot, probably thinking intelligent thoughts. L.Miguel Bugallo Sánchez/Wikimedia Commons

Parrots are exceptionally intelligent animals. They use tools, boast sophisticated problem-solving abilities, understand mathematical concepts and, of course, excel at "speaking." Now, as Catherine Griwkowsky reports for the StarMetro Edmonton, Canadian researchers may have unlocked one of the secrets of parrot intelligence: a unique brain circuitry similar to one found in primate brains.

In their quest to unpack parrots’ impressive smarts, researchers at the University of Alberta and the University of Lethbridge sourced 98 samples from the University of Lethbridge’s collection of bird brains—one of the largest in the world. The brains they analyzed came from a range of avian species, including owls, chickens and hummingbirds.

More specifically, the team wanted to find out if parrots have large pontine nuclei, a neural circuit that, in humans and other primates, transfers information between two areas of the brain: the cortex, which governs sensory information and other higher functions, and the cerebellum, which is responsible for motor functions.

This is like a huge highway that is travelled, sending information between these two main areas,” Cristián Gutiérrez-Ibáñez, part of the research team, tells CBC News. Compared to other animals, humans and primates have large pontine nuclei, so this enlarged brain structure is thought to play an important role in higher intelligence.

But the team’s results, published recently in Scientific Reports, showed that parrots do not have large pontine nuclei. In fact, this area of the brain is very small in birds, even parrots. Instead, they found that parrots had an enlarged medial spiriform nucleus, or SpM. Mammals do not have this circuit, but it seems to perform a similar function, passing messages between the cortex and cerebellum.

“It's actually two to five times larger in parrots than in other birds, like chickens," Gutierrez-Ibáñez explains in a statement. “Independently, parrots have evolved an enlarged area that connects the cortex and the cerebellum, similar to primates.”

The presence of large, corresponding neural connectors in parrot and primate brains might explain why parrots are able to engage in a variety of complex tasks. Parrots can, for instance, crack open a seed using their beaks and their claws, relying on the motor skills and intelligence that primates deploy when they use their hands.

“This is another fascinating example of convergence between parrots and primates,” Gutierrez-Ibáñez says. “It starts with sophisticated behaviours, like tool use and self-awareness, and can also be seen in the brain. The more we look at the brains, the more similarities we see.”

As George Dvorsky of Gizmodo points out, the new study raises a number of intriguing questions that researchers cannot yet answer. Why, for instance, do crows and ravens display advanced intelligence when they do not seem to have an enlarged medial spiriform nucleus? And how, exactly, does the SpM work?

"This could present an excellent way to study how the similar pontine-based process occurs in humans," Gutierrez-Ibáñez notes in the statement. "It might give us a way to better understand how our human brains work."

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