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For the birds: the soundscape of avian dreams and a bird-eye camera

by Fionna Samuels
June 24, 2024 | A version of this story appeared in Volume 102, Issue 19


Listening to avian dreams

A bird with a yellow belly and black wings appears alseep on a branch. Bars of music float around its head.
Credit: Madeline Monroe/C&EN/Shutterstock
Singing in their sleep: Scientists listen in on avian dreams.

When birds dream, they dream in song. Or at least that’s what Gabriel Mindlin’s recent study of dozing great kiskadees suggests. And he’s devised a way to listen in (Chaos 2024, DOI: 10.1063/5.0194301).

Previous studies have shown that neurons in bird brains do fire during their slumber, teasing that our feathered friends might be dreaming. Unfortunately, interpreting how that neural activity is linked to behavior is difficult. “We don’t know the language of neurons so don’t know how the pattern of activity is translated to generate the sound,” Mindlin tells Newscripts.

Luckily, singing is a physical endeavor as well as a mental one. When a bird sings, it modulates its tune with a combination of air flow and muscle contractions, all triggered by electrical impulses. In his lab at the University of Buenos Aires, Mindlin surgically places electrodes in the bird’s voice box to measure these electrical signals.

Mindlin first worked with conscious birds, spending years measuring the electricity in singing birds’ twitching voice muscles. He then created a relatively simple mathematical model to capture the relationship between electrical activity and song.

With that model in hand, it was an easy task for Mindlin to capture the electrical activity in a bird’s voice box during sleep and translate it into a synthetic song. When the first notes from this experiment came out of his computer speakers, Mindlin tells Newscripts he started laughing in delight. “I wasn’t even thinking about publishing; I was just having a blast.”

Mindlin’s work with sleeping birds isn’t just a flight of fancy, however. Like many birds, great kiskadees are not born with an innate knowledge of love songs or battle cries: they must learn their songs from a mentor. This connection between behavior and brain modification may lend insights into how vocal learning occurs across species. The next step for Mindlin will be to play the dreamt-up tunes back to the bird and look for behavioral changes—maybe the birds are learning in their dreams.

Mindlin didn’t begin his career as a birder, but after years of working with the feathery creatures, he now walks his neighborhood listening for individual birds and their protégés. The chingolo, or Andean sparrow, is one of his favorites. “I listen to these guys all the time,” he laughs, “I know their stories, I know their babies, and I know who the most successful teachers are.”


Eagle-eyed camera

Birds aren’t just a model for learning—their physiology can be an inspiration for new technology. A raptor’s eye is a marvel. Some species can see ultraviolet light, and others can spot rabbit-sized prey from 1.6 km away. Awed, a group of researchers led by Dae-Hyeong Kim at Seoul National University has fabricated a camera to mimic these impressive capabilities (Sci. Robot. 2024, DOI: 10.1126/scirobotics.adk6903).

An bald eagle looks at the viewer with a camera lens for its eye.
Credit: Madeline Monroe/C&EN/Shutterstock
A bird’s-eye viewfinder: A new camera mimics a raptor's sharp eyesight.

Avian biology was not the expertise of these engineers going into the endeavor, the researchers tell Newscripts. But for the past 5 years, they took to the subject vigorously, even visiting the zoo to observe and photograph eagles.

From this research, the team fabricated a camera with an artificial fovea—a depression within the eye where sight is sharpest—and a perovskite-based image sensor. This highly tunable material allowed the scientists to create a sensor array that mimics the four types of photoreceptors found in raptors’ eyes.

With a fovea and four different kinds of artificial photoreceptors, the new camera is uniquely able to capture multispectral images of distant objects while still maintaining a wide field of view. As the researchers continue to refine the design, they hope it will one day find use anywhere that requires a bird’s-eye view.

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