Biologists have observed spiders catching and eating frogs and toads in tropical Africa. The frogs often exceed the spiders in size.

Some spider species are known to be specialized in catching small fish from the vegetation overhanging the water. Much less well known is that spiders also catch small frogs and their tadpoles. A Belgian spider specialist and two specialists in African frogs – one is our recent vertebrates conservator Olivier Pauwels – teamed up to document this striking predator-prey relationship.

Together with other African and European biologists they compiled a list of known and new observations of spiders preying on frogs. This odd-looking behavior has been observed in a dozen countries in Sub-Saharan Africa, from Ivory Coast to South Africa.

How do they catch their prey? Spiders harpoon surfacing tadpoles with their maws. Frogs and toads are chased in the vegetation surrounding the water. Often, the frogs exceed the spiders in size.

Most of the frog-eating spider belong to the Pisaurid family. The paper is published in Bulletin of the Chicago Herpetological Society.