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What Spitting Cobras are Aiming For

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Make most cobras angry, and they’ll bite you and inject the bite with a dose of venom. Frighten or tick off a spitting cobra, though, and it will contract the muscles around its venom glands and “spit” it out through holes in the tips of its fangs. Right into your face. 

Spitting cobras are no slouches when it comes to marksmanship. Neurobiologist Bruce Young found this out when he put on a plastic face mask a few years ago and taunted cobras into taking more than a hundred shots at him. When he analyzed the snakes’ movements, he found that they always spit right after he made a jerky movement with his head. The snakes would turn their heads in the same direction that he’d started to move his and then start spitting. Tracking the target like this, Young wrote in his study, “gives cobras a distinct geometric advantage; even relatively large linear movements on the part of the target can be accommodated by rather modest angular movements of the cobra's head.” A burst of speed when turning their heads also lets the snakes “lead” the target a little and compensate for the time it takes for their muscles to send the venom flying. 

It’s a cool tactic, but not as easy as just biting whatever it is that needs biting. You see, spitting cobra’s venom doesn’t do anything if it just hits you on the skin or even gets in your mouth. To be of any use, the venom has to get in your eye, where it causes searing pain and can scar the corneas and leave you blind.

This has had many biologists wondering if the cobras know to shoot for the eyes and are aiming at them. Given the snakes’ accuracy when spitting and the limited targets that their venom is effective on, scientists, zookeepers and others who study and work with spitting cobras assumed they were. In 2005, researchers from the University of Bonn in Germany backed these assumptions up with an experiment. They put undergrad student Katja Tzschätzsch face-to-face with 10 different cobras and got them to spit at her hands, her face and life-sized photos of faces. Hands and still faces and photos didn’t get a rise out of the snakes, but a moving face (real and fake) did—less so when the eyes were digitally removed from the photos than when they were left intact. When the researchers looked at the traces of venom on the photos and Tzschätzsch’s facemask, they found that the different cobras hit the eyes anywhere from 80 percent to 100 percent of the time.

Now a newer study suggests that maybe the cobras aren’t so picky when choosing their targets. Guido Westhoff, a neurobiologist who worked with Young and Tzschätzsch on the previous research, revisited the question last year with another round of experiments. He and his team presented cobras with life-size, human face-shaped boards with and without different kinds of glass eyes, as well as larger and smaller fake faces and triangular boards that didn’t resemble faces. 

In 324 spitting tests, the snakes didn’t spit at the boards with eyes any more than the ones without. Also, when the eyes on the targets were moved closer together or farther apart, the snakes didn’t adjust their aim to account for the distance between them. Given a choice between a face with eyes and an eyeless one, the snakes spit at the larger target most of the time, whether it had eyes or not. 

Westhoff now thinks that cobras don’t specifically aim for the eyes, but for the center of whatever body part their tormenter puts closest to them. Often, this just happens to be the face—and it seems the snakes prefer more face-like round targets than pointy ones; they spit at those almost four times as much—and at least one eye gets hit by chance. 

What’s more, he thinks that aiming for the eyes is both unnecessary and even a bad strategy for the snakes. Cobras can spray their venom over a wider area by moving their head as they spit and spitting several times in a row, increasing their chances of hitting the eye and without requiring them to aim right at them. Shooting for eyes instead of just a face also puts a cobra at a disadvantage if it can’t clearly see or recognize eyes, like when their own eyes become cloudy while they shed their skins, or in the dark. 

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Animals
7 Fun Facts for World Elephant Day
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Happy World Elephant Day! Celebrate the occasion with some facts about everyone's favorite gentle giant. 

1. ELEPHANTS CAN RECOGNIZE OTHER ELEPHANT CARCASSES.

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The University of Sussex's Karen McComb told National Geographic that elephants "become excited and agitated if they come across a dead elephant," and, in particular, will investigate skulls and tusks. McComb teamed up with researchers at the Amboseli Elephant Research Project in Kenya to study the behavior, showing wild elephants a range of objects that included skulls. They found that the elephants examined skulls—and tusks in particular—of their own kind twice as long as other skulls, and examined tusks six times as long as they did pieces of wood. They were even able to recognize elephant skulls with the tusks removed, but didn't show preference for certain elephant skulls over others, which suggests they didn't know which skulls belonged to their own relatives. "Animals that are intensely social in life may be most likely to display an interest in their dead," McComb told National Geographic. "But what goes on in their minds while they are doing this is a total mystery."

2. THEY'RE SCARED OF BEES.

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Forget about mice scaring off elephants: When farmers need to keep elephants away from their crops, they should use bees. Researchers in Kenya discovered that even the recorded sound of buzzing bees was enough to make elephants retreat—and cause them to emit low-frequency sound, inaudible to humans, that warns other elephants. "It's impossible to cover Africa in electric fences," Lucy King, author of the paper, told the Huffington Post. "The infrastructure doesn't exist in many places and it would restrict animals' movement." But something like a bee fence—hives strung on strong wires a certain distance apart that would move when elephants walked into them, disturbing the hives—"could be a better way to direct elephants away from farmers' crops," she said.

3. THEY MIGHT UNDERSTAND POINTING.

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Human adults and babies often use pointing as a way to nonverbally get a message across, but not many other animals grasp the concept. But according to a two-month study of 11 tame African elephants, these pachyderms might be able to: When presented with two identical buckets and pointed in the direction of the one containing food, elephants picked up on the cue fairly consistently: Elephants had a success rate of 67.5 percent (1-year-old humans have a success rate of 72.7 percent). But an earlier study of Asian elephants indicated that they don’t notice pointing gestures, which is a bit of a mystery.

4. ONE ELEPHANT CAN "TALK." 

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Koshik, an elephant in a South Korean zoo, developed the ability to imitate the sounds of five words he's heard from his trainer—annyeong (hello), anja (sit down), aniya (no), nuwo (lie down), and joa (good)—by sticking his trunk in his mouth. The scientists who first noticed Koshik’s ability speculate that he learned to “talk” because he was lonely.

5. THEY'RE DIGITIGRADES.

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It's Latin for "finger walking," and what it means is that elephants walk on their toes (there are five of them, as well a sixth false toe). According to the book Mammal Anatomy: An Illustrated Guidemost of the animals' weight "rests on a broad pad of elastic tissue behind the toes" which "acts as a shock absorber and prevents the skeleton from jolting too much when the animals walk. It also allows elephants to move surprisingly quietly despite their size."

6. AN ELEPHANT PREGNANCY LASTS ABOUT TWO YEARS.

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If you thought being pregnant for nine months was bad, be glad you're not an elephant, which can be pregnant for up to 680 days, according to the BBC. All that time in the oven has a benefit, though: Elephant calves are born with highly-developed brains, capable of learning their herds’ complex social structures and ready to put their trunks to use.

7. NINETY-SIX ELEPHANTS ARE KILLED IN AFRICA EVERY DAY.

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Unfortunately, elephant poaching remains a very big problem: An estimated 35,000 elephants are killed annually, their tusks sold illegally in the ivory market. Do the math, and that comes out to nearly 96 elephants every day. Find out what you can do to help elephants and stop poaching at 96Elephants.org.

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Animals
Audible Launches 'Audible for Dogs' to Help Pet Parents Calm Their Stressed Canines
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In addition to a mutual love of hamburgers and lazy sunny afternoons in the backyard, dog owners can now share their affinity for audiobooks with their furry friends. As Fast Company reports, Audible has launched Audible for Dogs, a new service designed to keep canines relaxed while their owners are away from home.

Some people play music for lonely dogs, but according to an Audible press release, a 2015 academic study revealed that audiobooks worked better than tunes to calm stressed-out pets. To investigate the phenomenon further, Audible teamed up with Cesar Millan, the dog behaviorist who’s better known as the "Dog Whisperer." Their own research—which they conducted with 100 dogs, in partnership with Millan’s Dog Psychology Center in Santa Clarita, California—found that 76 percent of participating dog owners noticed that audiobooks helped their pets chill out.

Dog owners can play Cesar Millan’s new Guide to Audiobooks for Dogs—which is both written and narrated by Millan—for initiation purposes, along with a curated rotating selection of dog-focused audiobook titles including Trevor Noah’s Born a Crime: Stories from a South African Childhood, performed by Trevor Noah; Jane Austen’s Pride and Prejudice, performed by Rosamund Pike; and W. Bruce Cameron’s A Dog’s Purpose, performed by William Dufris. Each title features a special video introduction by Millan, in which he explains why the book is suited for doggy ears. (Pro tip: According to Audible’s research, dogs prefer narrators of the same gender as their primary owners, and books played at normal volume on an in-home listening device.)

Don’t have an Audible subscription, but want to see if your dog succumbs to the purportedly calming magic of audiobooks? New listeners can listen to one free Audible for Dogs selection with a 30-day membership trial.

[h/t Fast Company]

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