Heterogeneity among floral visitors leads to discordance between removal and deposition of pollen

Flowers are often visited by many species of animals. These sometimes differ in size, behavior, and other characteristics that translate into differences in their effectiveness as pollinators. The differences may be manifest in their effect on reproductive success either through female or through male function. A number of recent studies have measured pollen removal as a component of male function however, high pollen removal need not result in high subsequent deposition of the removed pollen or in high success at siring seeds. Here we provide an example in which pollen-collecting bees remove more pollen but deposit less of it than nectar-collecting bees. The pollen collectors are antagonists with regard to the male reproductive success of the plants, at least relative to the more beneficent nectar collectors. Our results underscore the need to study pollen deposition in conjunction with pollen removal.