Competition for pollination can occur between sympatric plant species sharing pollinators, but can be minimized if each plant species places pollen on different areas of the pollinator’s body. Hitherto there has been little field evidence to support the theory of differential pollen placement. Stewart and Dudash examined a community of five night-blooming plant species in Southern Thailand that share common bat pollinators, collecting pollen samples from the fur of four body parts of the wild foraging nectar bats and documenting changes to pollen loads throughout the night.
Each bat-pollinated species generally placed pollen on separate areas of the bat, according to clearly demarcated preferred patterns of pollen placement that either remained constant or became more distinct over time. The authors conclude that minimal interspecific pollen transfer occurs among Old World bat-pollinated plants, and that nectar bats are effective pollinators throughout the foraging period.
Stewart, A. B., & Dudash, M. R. (2016). Field evidence of strong differential pollen placement by Old World bat-pollinated plants. Annals of Botany, 119(1), 73–79. https://doi.org/10.1093/aob/mcw212