The drumming you hear outside your cottage window each morning could be a lot more complicated than initially thought. Woodpeckers, as it turns out, share a specialized brain region with vocal learners, a new study has found. Vocal learning is the ability to modify sounds through imitation and interactions with other individuals. The best example is humans learning to speak. We can learn and vocalise new words and sounds based off of hearing others speak.
The ability is rare. Only five mammal species are capable of vocal learning, including humans, elephants, and bats, and only three lineages of birds: songbirds, parrots, and hummingbirds. But now woodpeckers may join the list.
Woodpeckers can often be heard drumming their beaks on trees and metal surfaces, such as tin roofs and gutters. This is a different type of drumming than the one used to drill for insects or excavate nest cavities. This drumming is more rhythmic and can change frequencies. Woodpeckers use this drumming to communicate behaviour, most often attracting mates or negotiating territorial interactions with other woodpeckers, similar to the way some species use birdsong.
Woodpeckers will increase the speed of their drumming and the length of the beats to display a threat to competitors. In response, the competitors may try to match the tempo of the drumming. A woodpecker’s drumming is also thought to reveal individual identities. Woodpeckers can identify familiar birds versus ones they’ve never encountered before by the rhythm of the drumming.
To uncover this capacity for vocal learning, researchers examined the brains of seven bird species: a hawk, turaco, flamingo, penguin, emu, duck, and woodpecker. Researchers were looking for the presence of parvalbumin, a gene found in a cluster of nerve cells, also known as nuclei, in the birds’ forebrains. Most of the birds lacked the gene, but three regions of the woodpecker’s brain showed high parvalbumin activity.
Researchers performed the initial test on a single, male downy woodpecker. To confirm their theory, they tested both male and female brains of multiple woodpecker species, including hairy woodpeckers and red-bellied woodpeckers. All woodpeckers returned signs of the parvalbumin gene.
When drumming or listening to other woodpeckers drumming, these regions of the birds’ brains showed increased parvalbumin activity. This shares a close resemblance to the neurological patterns in songbirds when exhibiting song control. Both require command over complex muscle coordination. The main difference is that parvalbumin contributes to a songbird’s control over its respiratory system and syringeal muscles—emitting sound—whereas researchers theorize that parvalbumin helps control the woodpecker’s neck and head muscles.
One question researchers have yet to answer is how woodpeckers learn these drumming rhythms. Songbirds learn songs at an early age, absorbing the sounds even before they’ve hatched. Researchers theorize that woodpeckers could do the same, or that the birds learn features of drum rhythms through interactions with other species, modifying a drum template they were born with.
“Studies that explore the learned basis of drumming are underway,” the study’s researchers said.