A tarantula the size of a dinner plate was recorded by scientists as it dragged a young opossum across the leaf-litter of the Amazon jungle.
The grizzly encounter, documented for the first time, featured in a journal article that showcases attacks on small mammals by arthropods—mostly spiders—witnessed by zoologists in the Peruvian jungle.
A couple of times a year, biologists from the University of Michigan take a trip to Peru to study predator-prey interactions, often at night, when the ambush predators come to life.
One night, researcher Michael Grundler “heard some scrabbling in the leaf litter.”
“We looked over and we saw a large tarantula on top of an opossum,” said Grundler, a co-author of the paper in a statement. “The opossum had already been grasped by the tarantula and was still struggling weakly at that point, but after about 30 seconds it stopped kicking.”
Grundler’s sister Maggie pulled out her cellphone and shot photos and some video.
The encounter was one of the cases featured in an article published in Amphibian & Reptile Conservation.
The tarantula was the size of a dinner plate, and the young mouse opossum was about the size of a softball, according to a university statement.
They published other gruesome images of spiders with unusual prey.
“This is an under-appreciated source of mortality among vertebrates,” said evolutionary biologist Daniel Rabosky. “A surprising amount of death of small vertebrates in the Amazon is likely due to arthropods such as big spiders and centipedes.”
Arthropods are invertebrates with segmented bodies and jointed limbs and appendages: the animal world equivalent of wearing jointed suits of armor.
According to the researchers, an opossum expert at the American Museum of Natural History confirmed it was first documentation of a large mygalomorph spider—the group of the largest heavy-bodied—preying on an opossum.
“We were pretty ecstatic and shocked, and we couldn’t really believe what we were seeing,” Grundler said. “We knew we were witnessing something pretty special, but we weren’t aware that it was the first observation until after the fact.”
Over the years of charting life-and-death struggles between vertebrates and arthropods, the scientists had enough material to take the unusual a step of compiling a scientific paper, featuring 15 of their greatest hits.
“We kept recording these events, and at some point, we realized that we had enough observations to put them together in a paper,” said Rabosky, an associate professor in the Department of Ecology and Evolutionary Biology and an associate curator at the U-M Museum of Zoology.
Spiders are among the most diverse arthropod predators in the tropics. They have been recorded eating all major vertebrate groups: fish, amphibians, reptiles, birds, and mammals.
According to the university, knowledge of these interactions remains limited.