BASEL, Switzerland — Have a fear of spiders? A new study isn’t going to make you feel any better about these eight-legged critters. Researchers from the United States and Switzerland say they’ve discovered hundreds of incidents where these tiny predators have actually taken down and eaten an entire snake!
Dr. Martin Nyffeler, an arachnologist from the University of Basel, notes that spiders typically stick with trapping and devouring insects. However, Nyffeler and Professor Whitfield Gibbons from the University of Georgia found 319 incidents where spiders all over the world added something unusual to their menu.
Specifically, their study finds spiders on every continent except Antarctica eat snakes, and not just tiny ones either! Moreover, 80 percent of these snake-eating occurrences took place in the United States or Australia. Conversely, this “David and Goliath” matchup is extremely rare in Europe, making up less than one percent of these incidents.
Black widow is a real-life superhero
So what kind of a spider has the power to take down a foot-long snake? It turns out Marvel’s “Black Widow” isn’t the only one with super abilities and the strength to defeat larger opponents. Researchers find the real black widows are responsible for nearly half of all these successful snake killings.
These well-known arachnids have extremely powerful venom which contains a toxin that specifically targets the nervous systems of animals with backbones (vertebrates). This toxin is not only powerful enough to stop a snake, it’s even very harmful and painful to humans. Black widows also build their spider webs using extremely tough and resilient silk. Those webs are strong enough to capture larger animals, like lizards, frogs, mice, birds, and snakes.
Interestingly, the study also reveals spiders from 11 different spider families are capable of eating snakes.
“That so many different groups of spiders sometimes eat snakes is a completely novel finding,” says Nyffeler in a university release.
Spiders are giant-killers
Study authors discovered, along with a wide variety of families that can eat snakes, these spiders can outfight serpents that are 10 to 30 times their size! The largest snakes that spiders capture measure up to one meter in length. The smallest are about two inches long. On average however, spiders with exotic tastes tangle with snakes that are around 10 inches long.
The team adds, in most cases, the deciding factor in these battles is the spider’s venom — which can be potent enough to kill a human. With that in mind, researchers say learning more about how spider venom attacks the nervous system is an important goal for neurobiologists.
“While the effect of black widow venom on snake nervous systems is already well researched, this kind of knowledge is largely lacking for other groups of spiders. A great deal more research is therefore needed to find out what components of venoms that specifically target vertebrate nervous systems are responsible for allowing spiders to paralyze and kill much larger snakes with a venomous bite,” Dr. Nyffeler explains.
These snakes are no slouches
You might be thinking these sound like pretty weak snakes to lose to a spider, but you’d be wrong. The study finds around 30 percent of the time spiders attack and kill venomous snakes.
In the U.S. and South America, these spiders actually target extremely dangerous predators like rattlesnakes and coral snakes. In Australia, redback spiders (the Australian black widow) go after the brown snake — a member of the cobra family.
“These brown snakes are among the most venomous snakes in the world and it’s really fascinating to see that they lose fights with spiders,” Nyffeler concludes.
The study appears in the American Journal of Arachnology.
This article was first published June 29, 2021.