Eating frogs spiders

Spider eats vertebrates

Anyone who thinks that spiders only eat insects and other spiders is seriously mistaken. In the Amazon rainforest, biologists have now documented 15 cases of rather scary spider meals: The more than ten centimeters large wandering spiders devour frogs, lizards, snakes and even possums. In this photo a spider is eating a frog.

Daniel Rabosky from the University of Michigan and his team actually wanted to research the reptiles and amphibians of the lowland rainforest in the Amazon region. But the longer they dealt with the diverse and species-rich ecosystem, the more unusual interrelationships between their research objects and a completely different group of animals struck them:

"A surprisingly large number of small vertebrate deaths in the Amazon can be traced back to arthropods such as large spiders or centipedes," says Rabosky. "This is a previously completely underestimated cause of death in vertebrates." In order to get to the bottom of the matter, biologists have systematically documented such cases in recent years.

The result is not for the faint of heart: The researchers observe plate-sized wandering spiders attacking frogs and a lizard and paralyzing them with their venomous bite. This shot shows such an attack by a wandering spider on a frog of the species Leptodactylus didymus.

Spider kills possum

What was particularly creepy, however, was an observation made by the biologists during a nightly excursion: "We heard something rustling in the litter," they report. “We looked and saw a large tarantula dropping onto an opossum. At first the opossum defends itself weakly, but after about 30 seconds it was quiet. ”The spider had stunned the young mammal and was now about to eat it.

"We were shocked and could hardly believe what we were seeing," says Michael Grundler. “We knew immediately that we had witnessed something extraordinary. But only later did we learn that this was the first observation of such a case. ”According to the researchers, these cases demonstrate how complex and diverse food webs can be - and that predator-prey relationships can sometimes turn out the other way around than is commonly assumed .

Source: University of Michigan

March 1, 2019

- Nadja Podbregar