New observations of frog and lizard predation by wandering and orb-weaver spiders in Costa Rica

Studies have suggested that predation by spiders may be an important force regulating life history in neotropical frogs and lizards, but detailed descriptions of predator-prey relationships are few. Here we describe novel observations where spiders contributed to the mortality of frogs and lizards in northeastern Costa Rica, and we corrected or clarified three identification errors of spiders from the literature. The most frequently observed predators were wandering spiders (Ctenidae), which seem to be generalist predators on frogs and lizards. An orb-weaver spider (Araneidae) also contributed to frog mortality, likely after the frog became entangled in the spider’s web. More detailed studies are needed to elucidate the role that spider predation contributes to frog and lizard demography in neotropical forests.