Flower Visitation by Bats in Cloud Forests of Western Ecuador1

The importance of bat pollination has been demonstrated for many plant species. Yet this mutualism has rarely been studied on a community–wide level. In this paper we present results of a yearlong study of a bat–flower community in cloud forests on the western slopes of the Ecuadoran Andes. Of eight plant–visiting bat species caught, only Anoura caudifera and A. geoffroyi were carrying pollen. These species of Anoura supplement their diets with insects. Unlike glossophagines in other environments, however, which switch completely to a frugivorous or insectivorous diet during certain seasons, they are nectarivorous year–round and were never found with seeds or fruit pulp in their feces. Of the 13 morphotypes of pollen carried by the bats, 11 were identified to genus and 7 to species. Floral characteristics of all of these plants fit the traditional chiropterophilous syndrome well. Our study represents the first direct evidence of bat pollination for those plants identified to species, including four species of Burmeistera (Campanulaceae), as well as the first record of bat pollination for a plant of the genus Meriania (Melastomataceae). While overlap in the diets of the two Anoura was high, significant differences in visitation frequencies to particular plant species were detected. The larger bat species (A. geoffroyi) preferred large flowers, whereas the smaller species (A. caudifera) preferred small flowers.