Efficient avian pollination of Strelitzia reginae outside of South Africa

Abstract

In its native South Africa, endemic birds pollinate the complex flowers of Strelitzia reginae (bird of paradise) through a highly complex method of pollination. The plant is cultivated worldwide in warm-temperated regions but systematic pollination of the ornithophilous species by local birds has not been reported, and, consequently, seed production is rare outside of South Africa. We found that a member of the New World warblers, Geothlypis trichas, efficiently carried out pollination of S. reginae in southern California, thereby supplementing its typical diet of insects with the energy-rich nectar of S. reginae. Only occasionally, seeds were found in plantings not visited by these birds. The pollinator service provided by the warbler increases seed production in an area outside of South Africa. This could lead to adaptive changes in the exotic species, advance species establishment and persistence and possibly promote invasive behavior in a non-native environment.