Resource partitioning of prey types in Sarracenia purpurea.

Abstract

Resource partitioning, the division of resources such as nutrients and habitat space by organisms, is a way organisms may reduce competition. Pitcher plants, Sarracenia purpurea, live in nitrogen-poor environments where they must supplement their nitrogen intake by decomposing insects. This makes them prime candidates for intra-species resource competition to assure adequate amounts of nitrogen. In this study, we look at whether pitchers that vary in color, size and density attract different types of prey. We collected and recorded prey capture from 100 pitchers and identified most of the prey to three orders: Diptera, Coleoptera and Hymenoptera (primarily ants). We found that green pitchers attract a higher percentage of Diptera (ANOVA, p = 0.018), and that red pitchers seem to attract a higher percentage of ants (ANOVA, p = 0.059). We did not find an association between Coleoptera and pitcher color. There was no evidence for resource partitioning between pitcher diameter and pitcher density and prey capture type. Therefore, pitcher color may be a mechanism used by S. purpurea to partition resources, specifically prey capture type.