Flower-visiting bat species contribute unequally toward agricultural pollination ecosystem services in southern Thailand

Abstract

© 2016 The Association for Tropical Biology and Conservation The large majority of angiosperm species depend on animals for pollination, including many agricultural crops, and plant-pollinator interactions have been extensively studied. However, not all floral visitors actually transfer pollen, and efforts to distinguish true pollinators from mere visitors are particularly scarce among the bat pollination literature. To determine whether Old World bat species are equally effective pollinators in mixed-agricultural areas of southern Thailand, we examined six night-blooming plant taxa and quantified pollinator importance (PI) of seven common nectarivorous bat species. PI was calculated as the product of nightly bat visitation rate (obtained from mist-netting data) and pollen transfer efficiency (estimated from bat pollen loads). We found that PI varied by both bat species and plant species. In general, the nectar-specialist bat species were more important pollinators, yet their order of importance differed across our focal plant species. In addition, PI was dictated more by pollen transfer effectiveness than visitation rate. Our findings highlight the importance of Old World bat pollinators within southern Thailand's mixed-agricultural landscape and illustrate how seemingly similar floral visitors can have very different contributions toward plant pollination success.