Songbirds may have developed sharper senses to de-husk seeds
Songbirds, birds belonging to the Passeriformes order, are best known for their ability to produce complex musical sounds. Yet some songbird species also have another remarkable skill: They can easily remove the tough layer covering seeds (i.e., the husk) before swallowing their nutritious interiors.
Researchers at the University of Alberta, the University of Lethbridge and the Catholic University of Chile recently compared the brains of 92 different songbird species to uncover changes in the brain that may be linked to the emergence of seed-dehusking skills.
Their findings, published in Proceedings of the Royal Society B, suggest that the ability of some songbirds to dehusk seeds is supported by an enhanced sense of touch rather than stronger or more sophisticated movements.
"We have long been interested in how behavior drives the evolution of the brain in birds, particularly sensory systems," Cristián Gutiérrez-Ibáñez, co-author of the paper, told Phys.org.
"We are also interested in birds as a model for animals that manipulate objects without hands (birds' arms have turned into wings, which means they have lost hands and fingers). In our view, dehusking behavior is a perfect example for studying how the evolution of skilled manipulation, in this case with the beak and tongue, drives changes in the brain."
Examining the brains of 92 songbird species
As part of their study, Gutiérrez-Ibáñez and his colleagues examined the brains of 92 songbird species with different feeding habits. Some of these species are known to remove husks from seeds before swallowing them, while others have not developed this ability.
"We examined a large collection of bird brains that Professor Andrew Iwaniuk (one of my co-authors) collected over many years," explained Gutiérrez-Ibáñez.
"These brains were sectioned into very thin slices, mounted on glass slides and then stained so that we could see the different structures in the brain. We then measured the volume of different structures, in this case the areas that receive sensory, specifically touch-related, information from the beak and tongue, as well as those that control movement of the beak (motor areas)."
To dehusk seeds, songbirds rely on a combination of sensory signals, specifically information about the texture and position of seeds, and precise movements. The researchers thus closely examined parts of the brainstem known to play a role in the processing of tactile information and movement control.
They first measured the size of the principal sensory nucleus of the trigeminal nerve (PrV), an area that processes touch information gathered by songbirds via their beaks and tongues. They also looked at the trigeminal motor nucleus and facial motor nucleus, two nuclei in the brainstem that control the muscles prompting beak and tongue movements.
"We found that in birds that use the beak and tongue to peel the husk of seeds (dehusking), the area where the tongue is represented in the brain is enlarged," said Gutiérrez-Ibáñez.
"This is because these birds use mostly the tongue to hold and move the seed in the beak while they crack the seeds. We think this is analogous to the fingertips of primates, which are used to manipulate objects and are rich in touch receptors and overrepresented in the brain (in the somatosensory cortex). In short, a great example of convergent evolution."
Toward a better understanding of bird evolution
Interestingly, the researchers found that songbird species that could dehusk seeds did not have significantly larger motor nuclei (i.e., the areas supporting beak and tongue movements). However, their sensory brainstem nuclei, particularly the PrV, were larger than those of songbirds that could not remove the outer shell of seeds.
In the future, this recent study could help trace the evolution and diversification of songbirds. In addition, it could prompt other research teams to explore the contribution of brain regions involved in sensory processing to sophisticated dexterous behaviors.
"We now want to study the amount and distribution of touch receptors in the tongues of these different songbirds," added Gutiérrez-Ibáñez. "We would also like to look at other species that do the same. This includes some songbirds we didn't have access to, like African weavers and South American finches. We are also looking at other birds, like some parrots, which also dehusk seeds with the beak and tongue."
Written for you by our author Ingrid Fadelli, edited by Sadie Harley, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive. If this reporting matters to you, please consider a donation (especially monthly). You'll get an ad-free account as a thank-you.
Publication details
Cristián Gutiérrez-Ibáñez et al, Neural correlates of seed-eating in songbirds, Proceedings of the Royal Society B: Biological Sciences (2026). DOI: 10.1098/rspb.2026.0628.
Who's behind this story?
Freelance journalist with BSc Psychology and MA International Journalism. Covers AI, robotics, neuroscience, and astrophysics since 2018. Full profile →
BSc Life Sciences & Ecology. Microbiology lab background with pharmaceutical news experience in oil, gas, and renewable industries. Full profile →
Bachelor's in mathematical biology, Master's in creative writing. Well-traveled with unique perspectives on science and language. Full profile →
© 2026 Science X Network
Citation: Songbirds may have developed sharper senses to de-husk seeds (2026, August 6) retrieved 7 August 2026 from https://phys.org/news/2026-08-songbirds-sharper-de-husk-seeds.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.