Web inclination alters foraging success of a nocturnal predator

Abstract

In spider species, web inclination (vertical and horizontal webs) plays an important role in foraging success. However, these effects are poorly understood especially in such spiders that build both vertical and horizontal orb‐webs. Recent studies have shown that spider species with horizontal orb‐webs are specialized in preying aquatic insects emerging from the water. Females of a nocturnal orb‐weaving spider, Larinioides cornutus, are able to build both vertical and horizontal orb‐webs. Contrary to expectations, spiders which built horizontal orb‐webs made higher expenditures in the form of sticky spirals and captured less prey in comparison with females in vertical webs. Moreover, horizontal webs were not closely related to water, as might have been expected given their potential function of catching aquatic insects, despite the probability of successful foraging was generally higher in webs placed closely to water stream. On the other hand, the probability of a web being destroyed was higher in vertical orb‐webs, which may indicate that horizontal webs may be a compromise between more successful, but less lasting capture traps that would benefit from exposition during windless days and vice versa.