Global importance of vertebrate pollinators for plant reproductive success: a meta-analysis

Vertebrate pollinators are increasingly threatened worldwide, but little is known about the potential consequences of declining pollinator populations on plants and ecosystems. Here, we present the first global assessment of the importance of vertebrate pollinators in the reproductive success of selected flowering plants. Our meta-analysis of 126 experiments on animal-pollinated plants revealed that excluding vertebrate pollinators - but not insect pollinators - reduced fruit and/or seed production by 63% on average. We found bat-pollinated plants to be more dependent on their respective vertebrate pollinators than bird-pollinated plants (an average 83% reduction in fruit/seed production when bats were excluded, as compared to a 46% reduction when birds were excluded). Plant dependence on vertebrate pollinators for fruit/seed production was greater in the tropics than at higher latitudes. Given the potential for substantial negative impacts associated with the loss of vertebrate pollinators, there is a clear need for prompt, effective conservation action for threatened flower-visiting vertebrate species. Additional research on how such changes might affect wider ecosystems is also required.