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The secretary bird has one of the most deadly predatory strategies in all of the animal kingdom, but few would suspect this based solely on its peculiar appearance. Unlike most birds of prey, the secretary bird doesn’t rely on its talons to grasp at prey, nor on its beak to attack. Instead, it kills with a kick delivered with both staggering force and precision.
You wouldn’t believe the strategy unless you saw it for yourself: a bizarre-looking bird stalking through grasslands, taking down snakes with rapid stomps to the head. Yet as contrived as it sounds, researchers behind a 2016 study published in Current Biology brought this behavior into sharp scientific focus. For the first time in history, they quantified just how fast, how forceful and how neurologically demanding these strikes really are.
[…] The secretary bird (Sagittarius serpentarius) is found across the open grasslands and savannas of sub-Saharan Africa. Exposure is the primary issue that animals that inhabit these areas face: there are no dense forests to hunt within, nor any convenient perches for ambush.
Here, prey must move through the tall grass, where they intermittently become visible to predators. This means that they’re rarely caught unaware, as the openness of the land demands constant vigilance. For birds in such environments, the classic raptor strategy (i.e., spot from above, dive and seize) is much less reliable. So, the secretary bird does something different: it walks.
Stalks more like, but anyway.
“It takes deliberate, measured strides through the grass, actively disturbing its surroundings in order to draw out prey: rodents, lizards and snakes. And in such open terrain, where neither predator nor prey can find cover, encounters are usually direct. Once revealed, a snake can’t easily disappear – but it can’t be approached carelessly either. They’re fast, defensive and, in some cases, venomous; closing the distance to grasp the snake with its beak or talons would be risky.
Instead, the secretary bird maintains space. The sheer length of its legs makes it possible to strike from just beyond the snake’s effective range, which turns distance into a form of protection. And instead of grappling, it delivers rapid, forceful kicks aimed directly at the snake’s head, a target that reliably neutralizes the threat.
[…] To move beyond observation and into quantification, the authors of the 2016 Current Biology study trained a male secretary bird named Madeleine at the Hawk Conservancy Trust in Hampshire, England. By encouraging him to strike at a fake rubber snake, they were able to record detailed measurements of the bird’s kicking performance.
Their findings were astonishing. The average peak force of a secretary bird’s kick was measured at approximately five times its body weight, around 195 newtons. For an animal weighing just under four kilograms, to say this is a substantial mechanical output would be an understatement. It’s not merely a tap or a shove: it is a smashing, targeted blow.
And if its force weren’t enough, the speed of the impact is just as impressive. The researchers found that each kick made contact for just 15 milliseconds on average. For perspective, this is far shorter than the time it takes for the human nervous system to process and respond to tactile feedback.”
Off course this isn’t quite as fast as Chuck Norris, whose kicks could not be measured by any instrument known to man. But close.
[…] However, the speed and force of the strike are only half of the strategy. Delivering it accurately, under conditions where a mistake could be lethal, is just as important. On one hand, the strike must be powerful enough to stun or kill the prey. On the other hand, it has to be precise enough to target a small, mobile area (the head), while avoiding the danger zone of its fangs at the same time.
As the study highlights, this balance necessitates tight coordination between the visual and neuromuscular systems. Vision provides the spatial information for target tracking and locating, while the musculoskeletal system executes the movement itself.
There are several considerable constraints the secretary bird faces. As advantageous as the bird’s long legs are for reach and leverage, they also introduce delays in neural transmission. That is, the signals have to travel farther between the brain and the foot, which could, in theory, slow reaction times.
On top of this, it’s also possible that a single kick may not be sufficient, especially when dealing with larger or more resilient prey. As recorded in the 2016 study, secretary birds often deliver a series of rapid kicks in succession. And each one of these strikes must be recalibrated, re-aimed and executed with the same level of precision.”
Of course Chuck Norris could do it in one kick, but if you want to find an animal that comes even mildly close to Chuck, it’s the secretary bird.
They say that mother snakes used to tell their children not to bite Chuck Norris lest they die in agonising pain. But it’s also true that they tell their children to always look behind, or else the secretary bird will get them.
