Predation can take unexpected turns. For instance, various invertebrate
species - most commonly spiders - may prey on tetrapods. Here, we report
observations of spiders (Sparassidae, Olios sp.) preying on amphibians
(Hyperoliidae, Heterixalus andrakata) in north-eastern Madagascar. To do
so, the spiders built highly-specialized traps by weaving two leaves
together. Four cases by different individuals of the same species show
that spiders hide at the rear end of the trap. One case reports the
feeding on a small frog caught inside the trap. Previous reports on
amphibian predation by spiders describe opportunistic and indiscriminate
predation behaviour by generalist ground-dwelling or aquatic spiders.
The only more targeted cases concern large orb-weaver spiders building
large webs that may serve as an effective trap for small vertebrates,
but those only make up a small percentage of prey compared to insects.
In contrast, the novel traps type reported here seems to be solely
targeted at catching amphibians seeking shelter during the daytime. We
thus report systematic trapping of amphibian by spiders, a newly