Woodpeckers drumming on trees use the same part of the brain as songbirds learning a tune

Woodpeckers drumming their beaks on trees are using the same part of the brain as songbirds learning to sing a tune, a new study has found.

The bird’s forebrain contains specialized pecking regions that resemble those associated with bird song and human language systems.

These have previously only been found in bird species that learn and produce vocalizations, which is not the case with the woodpecker.

However, researchers at Brown University in the US found that these same regions are activated by the bird’s characteristic tree drumming.

The finding suggests that their ability to peck rhythmically has evolved in the same way as vocal learning in animals and language in humans.

The downy woodpecker forebrain contains specialized pecking regions that resemble those associated with bird song and human language systems (stock image)

The downy woodpecker forebrain contains specialized pecking regions that resemble those associated with bird song and human language systems (stock image)

Brain diagrams showing drum control nuclei and their connections in woodpeckers compared with similar nuclei and connections in vocal learning birds.  A: The song learning nuclei are RA, HVC, LMAN, and Area X. B: The drum control nuclei are arcopallium (dA), anterior nidopallium (dAN), and dorsal lateral nidopallium (DLN).  C: Nuclei for song learning and woodpecker drumming are not present in the brains of non-vocal learning bird species.

Brain diagrams showing drum control nuclei and their connections in woodpeckers compared with similar nuclei and connections in vocal learning birds.  A: The song learning nuclei are RA, HVC, LMAN, and Area X. B: The drum control nuclei are arcopallium (dA), anterior nidopallium (dAN), and dorsal lateral nidopallium (DLN).  C: Nuclei for song learning and woodpecker drumming are not present in the brains of non-vocal learning bird species.

Brain diagrams showing drum control nuclei and their connections in woodpeckers compared with similar nuclei and connections in vocal learning birds. A: The song learning nuclei are RA, HVC, LMAN, and Area X. B: The drum control nuclei are arcopallium (dA), anterior nidopallium (dAN), and dorsal lateral nidopallium (DLN). C: Nuclei for song learning and woodpecker drumming are not present in the brains of non-vocal learning bird species.

HOW DOES THE STUDY WAS REALIZED?

Scientists have known that certain birds learn to vocalize by imitating larger birds, while some are born with the ability.

To check for differences in brain activity between learners and non-learners, they visualized the brains of species in the latter group, including the downy woodpecker.

To their surprise, the woodpecker showed activity in areas of the brain that birds use to learn songs.

After playing the woodpeckers some drum sounds, the researchers found that it activated these brain regions.

This suggests that the birds might learn drumming patterns from their pecks, rather than vocalizations.

The brain regions they use for pecking may also have evolved in the same way as those used by other species for vocal learning.

Lead author Professor Matthew Fuxjager said: “Woodpeckers have a set of specialized brain areas that control their ability to rapidly drum or hammer their beak into trees and gutters, during fights with other birds.”

“Furthermore, these brain areas remarkably resemble the parts of the songbird brain that help these animals learn to sing.”

Woodpeckers bore holes in the bark of trees to create nesting cavities and catch food with their long tongues.

They perch vertically in trees and beat their bills repeatedly against the trunks, as if playing drums or drilling.

Birds also use noise to defend their territories and scare away potential intruders, similar to birdsong.

Both drumming and songbirds also require rapid and complex motor movements, and must be adaptable when the birds compete with each other.

These factors suggest that they may have neurological similarities, and songbirds are known to express a marker gene called parvalbumin (PV) that controls vocalization learning.

PV is also associated with language learning in humans, which is similar to bird song in that it is learned young and requires complex muscular coordination.

However, the gene has never been found in the forebrain of birds that do not learn their vocalizations.

Microscopic images of PV-rich forebrain nuclei in a song-learning hummingbird (green box) and a drummer woodpecker (red box).  White dashed regions indicate the boundaries of the song control regions.  Blue dashed regions indicate specialized PV regions.  Scale bar = 2mm

Microscopic images of PV-rich forebrain nuclei in a song-learning hummingbird (green box) and a drummer woodpecker (red box).  White dashed regions indicate the boundaries of the song control regions.  Blue dashed regions indicate specialized PV regions.  Scale bar = 2mm

Microscopic images of PV-rich forebrain nuclei in a song-learning hummingbird (green box) and a drummer woodpecker (red box). White dashed regions indicate the boundaries of the song control regions. Blue dashed regions indicate specialized PV regions. Scale bar = 2mm

Some birds, such as hawks, are born with the innate ability to vocalize, while others, such as songbirds and parrots, must listen and imitate older birds to learn how to do so.

For this study, published yesterday in PLOS Biologyscientists were testing whether the brains of birds that don’t learn their calls look different than those that do.

Previous research suggested that PV activity is increased in birds that learn their vocalizations, so they wanted to confirm that this was not the case in certain non-learning species.

This included flamingos, ducks, hawks, penguins, and the downy woodpecker, but to their surprise, they found that the latter had specialized brain regions that produce PVs.

These areas are similar in number and location to several of the forebrain regions that control song learning and production in songbirds.

Woodpecker drumming, like birdsong, could be a learned behavior, and has evolved in the same way as vocal learning in animals and language in humans (stock image)

Woodpecker drumming, like birdsong, could be a learned behavior, and has evolved in the same way as vocal learning in animals and language in humans (stock image)

Woodpecker drumming, like birdsong, could be a learned behavior, and has evolved in the same way as vocal learning in animals and language in humans (stock image)

To test how the downy woodpecker used that section of its brain, the researchers played drum sounds through speakers near their nesting cavities in the wild.

They then examined the forebrains of woodpeckers that drummed in response to sound and found that it triggered activity in PV brain regions.

This suggests that drumming, like birdsong, could be a learned behavior and has evolved in the same way as vocal learning in animals and language in humans.

These findings increase understanding of how brain systems evolve to perform new but similar functions.

Woodpeckers’ heads ‘act like stiff hammers’, not hard hats, study finds

Scientists have debunked a popular theory of how the woodpecker can repeatedly slam its beak into a tree at high speed without damaging its brain.

The researchers analyzed high-speed video of three species of woodpeckers: the pileated woodpecker, the black woodpecker, and the spotted woodpecker.

They discovered that their skulls do not act like shock-absorbing helmets as previously thought, but rather like rigid metal hammers.

In fact, their calculations show that any shock absorption would hamper the woodpeckers’ pecking ability.

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