Daddy longlegs spiders shock scientists as they gobble up unusual prey like ‘gummy bears’
More like daddy frog legs.
Although known for eating bugs and other invertebrates, it appears daddy longlegs are pursuing bigger game. Researchers observed these gangly arachnids chowing down on small frogs that are bigger than themselves in South America, as detailed in ribbeting research in the journal Ecology and Evolution.
“Finding these animals eating frogs was a complete surprise, we didn’t expect them to be able to capture them,” study co-author Luís Fernando García, a biologist at the University of the Republic in Uruguay, told Live Science.
The research team based their findings on ten reports of this French-evoking feeding behavior, which would appear to completely upend the typical predator-prey dynamic between bugs and amphibians.
These encompassed field observations across South America, research papers and submissions to iNaturalist — a citizen science platform where anyone can post wildlife pics.
Naturalist guide and co-author Lizardo Proaño told Smithsonian Magazine that he initially didn’t think he was seeing “something special” while observing a harvestman devouring one of these fly-catchers.
“I thought it was normal because frogs are good prey for everybody,” he said. “They don’t have any scales or hard bones. They are like gummy bears in the forest.”
He quickly learned that this behavior was quite the anomaly in scientific circles. Although the observations are nothing knew, it was unclear if these spindly-limbed critters were scavenging dead frogs or actively hunting them.
Given that these pond-hoppers were still alive in many of the instances, the team deduced that it was more likely the latter.
In some cases, the frogs were up to 1.29 times bigger than their captor — an impressive feat given that these creepy crawlies don’t have venom with which to subdue their prey.
Instead researchers speculated that these eight-legged invertebrates might be using their strong spiny mouthparts or front limbs, known as pedipalps, to grasp their slippery quarry like a preying mantis.
“They must rely entirely on physical restraint,” surmised Jose Valdez, an ecologist at Martin Luther University Halle-Wittenberg in Germany who was not involved in the study.
Researchers also suspected that the harvestmen could be targeting frogs that are injured, slow or even sleepy.
Why did these slender arthropods start hunting amphibians? Because they can, the researchers say.
“If they can capture one, why not eat one?” said study author Esteban Calvache, who works as a biologist at Mashpi Lodge and has observed this macabre feeding behavior.
He suspected that the famously non-picky daddy longlegs, which feasts on everything from worms to animal droppings, were simply taking advantage of the area’s bounty of amphibians.
In addition, the tropical species of harvestmen tend to be bulkier than their temperate counterparts, so they might rely on heartier prey animals like frogs to sustain their large bodies.
Further studies are needed to determine the method and frequency of this unique form of predation.
Coincidentally, harvestmen aren’t the only arthropods that target vertebrate prey.
The Goliath bird-eating spider, which is the world’s largest arachnid in the world, has been observed dining on everything from mice to birds, hence its name.
In turn, this mammoth tarantula is consumed by indigenous people in the South American jungles where it resides with some epicures comparing the furry arachnid’s flavor profile to crab or smoked shrimp.
