Woodpecker Behavior: The Surprising Physics of How They Hammer | Birding & Wildlife

Hidden beneath ​all⁢ their rum-pum-pumming,woodpeckers are quietly⁣ grunt-grunt-grunting.

The ‌birds exhale with​ each strike, much like a tennis pro groaning through a stroke. Elaborate coordination between those breaths and muscles across‍ the body keep their hammering at a perfectly​ consistent rate, ‌researchers report november 6 in journal of‍ Experimental Biology.

Research into the unusual capabilities of woodpeckers — ‍who can strike hundreds of times per ​minute at forces 20 to 30 times their ⁣body weight — has ‌largely focused on how they’re able to percuss without getting​ concussed. The new ⁢analysis simply asks how, at all?

While pecking might look like a simple back-and-forth head motion, ⁢“it’s actually a very arduous, skillful behavior that involves the movement of muscles across the body,” says Nicholas Antonson, a behavioral ⁢physiologist at Brown university.

Antonson and his colleagues humanely captured eight wild downy woodpeckers⁢ (Dryobates pubescens) from ⁣the ​Brown campus and surrounding area.⁣ They carefully inserted electrodes into eight different ⁤muscles, which measure electrical signals that ⁣indicate a muscle’s contraction. ‍Then, for a half hour at a time, the researchers observed ⁣the woodpeckers as ⁣they drilled (a behavior used to⁢ probe and excavate) and tapped (a behavior used‍ to communicate). ​Each bird wore a tiny custom-fit backpack to‌ record the electrical signals, which the⁢ team synced with ⁣high-speed video taken‍ at 250 frames per second. After a few days of observation and ⁣recovery, the birds were released.

The analysis revealed a complex choreography of muscle and breath that turns the bird into the⁢ equivalent of a hammer. When humans use ⁤a hammer, the muscles in the back of their wrist stiffen to reduce energy loss at impact; the⁢ researchers​ observed ​a ⁢similar ⁢stiffening in some of the woodpecker’s neck muscles. “It’s crazy just how similar it is to‍ the ⁤way we hammer,” Antonson says.

Other muscles played distinct roles throughout the striking motion. In the moments preceding, the birds appeared to brace ⁤themselves with ​their tail muscles, whereas the power of⁢ the strike itself was largely determined by the activation of a single⁣ muscle in the hip. Distinct head and neck muscles help to pull​ back the head after each beat, ‍activating before ⁢other muscles completed ⁤their forward ‌movement. The overlapping contractions may help smooth out the ⁤peckers’ back-and-forth movements during a rapid drum solo.

The ⁢team also looked at airflow through the syrinx — akin to a voice box — to determine ‍whether woodpeckers hold their breath upon a strike, like a⁣ weightlifter might, or exhale through the movement, more⁣ like a tennis player.⁤ Both strategies help stabilize core​ muscles ​during a movement​ — but downy woodpeckers take after tennis players. they can strike and exhale as many as 13 times per second, indulging‌ in a 40-millisecond inhale between‌ each blow.⁤ The movement’s timing stayed remarkably consistent over multiple taps,says Antonson.

Songbirds take mini breaths to support their lengthy tunes. That woodpeckers do the same “is suggestive​ that⁤ [tapping] might be more akin to singing​ than⁣ we had realized,” says Daniel Tobiansky, a behavioral neuroscientist who⁣ studies birds at‌ Providence college ⁤and‍ was⁢ not involved in the ⁤study. Nonvocal acoustic communication is frequently enough overlooked‍ in research of the animal ⁢kingdom, he says, and connections like these⁢ provide insights into how it may have‌ evolved.

Having taken a “look under the ‍hood”⁢ at downy woodpeckers, Antonson plans to continue exploring the mechanics of extreme behaviors performed by other ⁢species, to‍ see ⁤what insights they might serve up.