A Relative Measure of Predation on Web-Spiders in Temperate and Tropical Forests

Publisher Website
Google Scholar
Abstract
A relative measure of predation on web-spiders was determined for temperate (Pennsylvania, USA), subtropical (Peru) and tropical (Gabon) forests. Predation was quantified by comparing the losses of matched individuals in 4 treatment groups. Spiders in groups 1 and 2 were released on natural vegetation in the forest. Group 2 was paint-marked and group 1 was not. Groups 3 and 4 were paint-marked and released in cages constructed in the study areas. Group 3 spiders were released in cages with no tops. Group 4 spiders were released in complete cages. Both cages were open enough to allow the free movement of spiders and their insect prey. The number of spiders lost from groups 1, 2, and 3 during the daytime on the 2 tropical sites was significantly higher than losses in group 4 or during any other time period. Predation, at least by vertebrates, is probably more intense during daytime periods on those tropical sites.