The Geographical Differences in the Bird Prey of the Great Evening Bat (Ia io)

Abstract

Geographic variation in diet can indicate if species have unique ecological roles or feeding strategies in different environments. Bats have a unique nocturnal ecological niche and a diverse diet, making them an ideal model for studying changes in feeding. Some bats have adapted to reduced food resources caused by environmental changes and human disturbances by expanding their dietary ecological niche. As one of the typical species whose dietary niche has expanded from invertebrates (insects) to vertebrates (birds), the feeding habits of the great evening bat (Ia io) have attracted much attention from researchers. Unfortunately, little is known about how the diet of Ia io varies in different regions. Therefore, in this study, the diversity and composition of the bird prey of the great evening bat from two populations were examined using cytochrome C oxidase subunit I (COI) amplicon sequencing. The results showed that the great evening bat in both populations preyed on a variety of passerine birds, with the Phylloscopidae being the dominant family. Although most birds preyed upon by these two populations are the same, there are significant differences in predation on Cettiidae between the two populations. Both populations prey on migratory birds more than resident birds. Both populations of bats can prey on finch birds weighing more than 15 g, but they preyed on more birds weighing less than 10 g. The results of this study provide an important addition to the study of changes in bat diets under the conditions of expanding dietary ecological niches.