This Snake’s Venomous Powers Morph as It Grows Up

Snakes: Ian Macdonald / Art: Rebecca O'Connell
Snakes: Ian Macdonald / Art: Rebecca O'Connell

Our relationship to food changes as we age. Our metabolisms slow. We start carrying antacids when going out to dinner. Sometimes we’ll even intentionally eat vegetables. But our transformation has nothing on the brown snake, whose venom gradually morphs to accommodate its new eating habits. Researchers described the snake’s enviable aging process in the journal Comparative Biochemistry and Physiology, Part C: Toxicology & Pharmacology.

Australian brown snakes (genus Pseudonaja) pack some of the most deadly venom in the world. As the authors of the new paper note, brown snakes are also “responsible for the majority of medically important human envenomations in Australia.” And that's saying something.

To better understand how that venom works, researchers collected samples from adult and juvenile snakes from nine known Pseudonaja species. Then they tested each venom’s effect on blood and other substances.

Eight out of the nine species showed a distinct change in venom action between the snake’s youth and adulthood. Brown snake venom is known for its anticoagulant, or blood clot–preventing, properties, which can lead to deadly strokes in small animals and internal bleeding in humans. But only the grown-ups’ venom contained anticoagulants. The babies’ toxic spit had its own power: attacking the nervous system, causing paralysis.


Juvenile (L) and adult (R) brown snakes.
Snakes: Stewart Macdonald / Art: Rebecca O'Connell

The venom’s transformation over time is not random, lead author Bryan Fry, of the University of Queensland, says, but a brilliant adaptation to the snake’s preferred diet at different stages in its life. Baby brown snakes eat tiny lizards, while adults prefer meatier—but scrappier—mammalian fare like rodents. They need a venom that knocks out their opponents fast.

"Young brown snakes may produce clinical symptoms like that of a death adder, as they seek out and paralyze sleeping lizards,” Fry said in a statement. "Once older, their venom contains toxins that cause devastating interference with blood clotting, causing rodent prey to become immobilized by stroke.”

Within the adult snakes’ venom lay another surprise. Scientists knew that brown snake venom worked by converting one blood protein into another, but other snakes do that, too, and their venom isn’t as fast-acting. Some other, hidden process, was going on, and Fry and his colleagues found it.

"Our team discovered brown snakes are potent in activating Factor VII, another blood-clotting enzyme, which is the missing (dark matter) element of brown snake envenomations,” he said. "The feedback loop created by this enzyme would become a venomous vortex and dramatically accelerate the effects upon the blood."

Reminder: It’s not that brown snakes want to be responsible for medically important human envenomations. Like sharks and bears, they’d much rather be left to go about their business. So the best thing for you, and them, is to leave them alone.

Why Are There No Snakes in Ireland?

iStock
iStock

Legend tells of St. Patrick using the power of his faith to drive all of Ireland’s snakes into the sea. It’s an impressive image, but there’s no way it could have happened.

There never were any snakes in Ireland, partly for the same reason that there are no snakes in Hawaii, Iceland, New Zealand, Greenland, or Antarctica: the Emerald Isle is, well, an island.

Eightofnine via Wikimedia Commons // Public Domain

Once upon a time, Ireland was connected to a larger landmass. But that time was an ice age that kept the land far too chilly for cold-blooded reptiles. As the ice age ended around 10,000 years ago, glaciers melted, pouring even more cold water into the now-impassable expanse between Ireland and its neighbors.

Other animals, like wild boars, lynx, and brown bears, managed to make it across—as did a single reptile: the common lizard. Snakes, however, missed their chance.

The country’s serpent-free reputation has, somewhat perversely, turned snake ownership into a status symbol. There have been numerous reports of large pet snakes escaping or being released. As of yet, no species has managed to take hold in the wild—a small miracle in itself.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

Intense Staring Contest Between a Squirrel and a Bald Eagle Caught on Camera

iStock.com/StefanoVenturi
iStock.com/StefanoVenturi

Wildlife photographers have an eye for the majestic beauty of life on planet Earth, but they also know that nature has a silly side. This picture, captured by Maine photographer Roger Stevens Jr., shows a bald eagle and a gray squirrel locked in an epic staring match.

As WMTW Portland reports, the image has been shared more than 8000 times since Stevens posted it on his Facebook page. According to the post, the photo was taken behind a Rite Aid store in Lincoln, Maine. "I couldn't have made this up!!" Stevens wrote.

Bald eagles eat small rodents like squirrels, which is likely why the creatures were so interested in one another. But the staring contest didn't end with the bird getting his meal; after the photo was snapped, the squirrel escaped down a hole in the tree to safety.

What was a life-or-death moment for the animals made for an entertaining picture. The photograph has over 400 comments, with Facebook users praising the photographer's timing and the squirrel's apparent bravery.

Funny nature photos are common enough that there's an entire contest devoted to them. Here are some of past winners of the Comedy Wildlife Photography Awards.

[h/t WMTW]

SECTIONS

arrow
LIVE SMARTER