Looking out for the winged percussionist

April 2022. Late afternoon. Our farmhands were manuring crops as they bantered about village politics. I stood around eavesdropping shamelessly. Just then, furious knocking filled the air.

I scanned the tree canopies. ‘Rat-tat-tat-tat-tat-tat,’ the insistent drumming reverberated again. A flash of crimson and ochre blazed against the snag of the Indian mesquite tree. It was the female of a black-rumped flameback woodpecker, also called the lesser goldenback (Dinopium benghalense). I had on occasion watched the woodpecker’s undulating flight and had been startled by its high-pitched rattling calls, not unlike a shrill bugle.

The nattily attired bird sported a vermilion mohawk, a forecrown of stippled ebony matching the bib on the throat and the chest, a gilded cape, and elegant black on her rump. She accessorised the look with a nifty dark beak.

The male wears an entire crown of blazing scarlet. This winged jackhammer of the avian realm inhabits lowland forests, open country, and leafy urban suburbs.

Famed for its dizzying percussion prowess, the woodpecker lands up to 20 pecks on dense wood in a single second at a speed of 24 kilometres per hour, to dislodge succulent beetle larvae, ants, spiders, grasshoppers, and other insects. A sticky tongue, thrice as long as its pointy, sturdy bill, loops around the back of its skull and extends between its eyes, helping ferret out grub from tree crevices.

The bird adroitly forages up and down tree trunks. A stiff tail and a pair of zygodactyl feet with two toes pointing forward and two backwards, lend balance and grip.

If you and I attempted ramming headfirst into a tree trunk, the consequences would be morbid! How does the woodpecker pull it off without incident? A bunch of sophisms abound, including an unsubstantiated hypothesis that the bird has a thick skull and foam-like tissue that cushions its brain from injury. Does this hypothesis hold water? Lorna Jane Gibson, a Professor of Material Science and Engineering at the Massachusetts Institute of Technology who studies the mechanical behaviour of foam, and an avid birdwatcher herself, decided to investigate, and found this theory to be groundless. Gibson instead reveals the following adaptations behind the woodpecker’s superpower.

First, a brain that is eight times smaller than a human brain allows woodpeckers to withstand larger deceleration, which is the rate of slowing down of an object. Sudden deceleration causes accidents and injuries. Human brain injury occurs at a deceleration rate of 100 G (the gravitational force between two objects). Due to a smaller brain size, woodpeckers can endure 16 times the deceleration rate of a human brain. Think scaling — at 2.5 grams, the bird’s brain weighs barely more than a cashew kernel, and is tightly packed within a compact skull, reducing its motion on impact, while a human brain is said to weigh 1.4 kilograms, and sloshes about in cerebrospinal fluid in a roomy skull.

Next, a larger surface area of the woodpecker’s brain is oriented forward such that any impact gets distributed across, unlike the human brain that sits like a hemispherical cap within the skull, with any frontal or rear impact concentrated on a small area of the brain, causing extensive injury. Finally, the shorter the duration of G-force, the less its impact on the body, and the woodpecker takes less than a millisecond to go from full force to deceleration when the beak hits the tree, limiting its G-force exposure. This is also the backstory to why F1 race drivers can survive a deceleration of 200 G without injury — it barely lasts a couple of milliseconds.

Simply put, Gibson attributes the woodpecker’s smaller brain size to its incredible headbanging exploits. For the male woodpecker, drumming is an assertion of territory, and his love language, too. Rhythmic, energetic drumming signals a healthy, dependable mate capable of chipping perfect nests. The male even boogies and serenades his lady love with ditties during courtship.

These birds are cavity nesters with both partners sharing in nest-chipping. The female lays between two and four eggs, and the doting parents take turns incubating the eggs for around 12 days. A new generation leaves the nest in about 20 days.

Rooting for Nature is a monthly column on an off-kilter urban family’s trysts with nature on a natural farm. The author runs Green Goobé, a sustainable venture. Reach her at [e-mail]