‘Almost Unbelievable’: Spiders Feeding on Snakes
A recent study reveals that dangerous spiders hunt on snakes many times their size — and frequently emerge victorious against snakes as venomous as they are.
The researchers discovered 319 instances of spiders killing and dining on snakes, 297 of which occurred naturally in the wild. (The last 22 performances took place in captivity.) Around a third of those examples came from scientific observations published in peer-reviewed journals, while the remainder were discovered on news or social media websites.
“The longer I deal with this problem, the more I realize that certain spiders accomplish such incredible feats,” said study co-author Martin Nyffeller, a conservation biologist at the University of Base who has previously published research on spiders eating bats and other vertebrates.
Related: View images of spiders consuming bats
Spiders are mighty
Snacking on snakes was surprisingly prevalent, with over 30 spider species engaging in the practice in natural settings and another 11 doing so in captivity, Nyffeler and University of Georgia herpetologist J. Whitfield Gibbons reported in the Journal of Arachnology this month.
Widow spiders were the most often encountered spiders, accounting for approximately half of all snake deaths; this group includes the infamous hourglass-marked black widows (Latrodectus mactans, L. Hesperus, and L. variolus), as well as relatives such as the African button spider (L. indistinctus).
Although these spiders are little, measuring no more than 0.4 inches (1.1 cm) in length, and mainly prey on small, juvenile snakes, their venom is lethal enough to kill many larger species.
Related: View photographs of spiders devouring snakes
Another 10% of snake deaths were caused by members of the tarantula family. These larger spiders do not weave webs, preferring to pursue prey on the ground or in trees.
Additionally, 8.5 percent of predation episodes were committed by big orb-weaver spiders, which are known to trap and eat bats and birds. These spiders spin massive, extremely strong circular webs. After suffocating the snakes, the spiders suck out their insides, just like they would an insect.
Spiders devouring snakes was documented on every continent except Antarctica, while over half of the reported incidents occurred in the United States and nearly a third in Australia.
Victims who are sinuous
The researchers discovered evidence of spiders preying on 86 distinct kinds of snake, with colubrid snakes being the most frequently attacked. This family includes common species such as garter snakes (Thamnophis cyrtopsis) and rat snakes (Pantherophis guttatus), and their abundance among spider victims likely reflects their dominance on all continents except Australia, Nyffeler and Gibbons stated.
The majority of spider-attacked snakes were infants or juveniles weighing less than a gram. However, spiders occasionally snatched big serpents: the largest victims measured up to 3.25 feet (100 centimeters) in length and weighed several ounces.
Orb-weavers or big tarantulas were generally responsible for the death of such enormous snakes. Black widows may outweigh snakes up to 30 times their own weight, and according to one story, a cobweb spider (Steatoda triangulosa) entangled a 6-inch (15 cm) garter snake that weighed 355 times as much as the spider.
“Such an achievement is truly surprising,” Nyffeler told Live Science. “It is almost unbelievable.”
It may take hours or days for the spider poison to kill the snakes, 30% of which were dangerous in their own right. In 86 percent of reported occurrences, spider attacks killed snakes, whereas just 1.5 percent of snakes escaped on their own. An additional 11% were saved by human observers.
Once a spider defeats a snake, the feast may take days to complete.
In the majority of cases, the researchers concluded, snakes are an uncommon and fortunate meal for spiders that generally feed on insects. However, some spiders, notably tarantulas, may consume snakes on a regular basis. Australian redback spiders (Latrodectus hasselti) have also been observed consuming big numbers of lizards and snakes.
Nyffeler admitted to having a snake phobia, yet the research mingled horror with interest.
“After studying the ‘world of spiders’ for a lifetime, it was very fascinating to get a glimpse into a parallel world, the ‘world of snakes,'” he explained.
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Live Science originally published this article. The original article can be found here.