Gleaning bats as underestimated predators of herbivorous insects: diet of Micronycteris microtis (Phyllostomidae) in Panama

Abstract

Abstract:Predators of herbivorous insects play important roles in tropical ecosystems as herbivory may affect structure and diversity of plant populations. Although insectivorous bats are particularly abundant and diverse in the tropics, their impact on herbivorous insects is little understood. To assess prey consumption, we observed the gleaning bat Micronycteris microtis (Phyllostomidae) continuously for 3 mo including 16 full nights at a nightly feeding roost on Barro Colorado Island in Panama using infrared videotaping combined with collection of prey remains. Individual bats consumed about 61-84% of their body mass in arthropods per night. Diet analysis revealed a high percentage of herbivorous insects, constituting more than half (51%) of all prey and over 70% of prey biomass. Dominant prey were caterpillars (33% of prey biomass), and other herbivores including crickets, katydids, scarab beetles and phasmids. Furthermore, a novel feeding behaviour was observed as M. microtis selectively discarded parts of intestines of phytophagous insects before consumption, probably to avoid intake of plant material either for ballast reduction and/or for protection from secondary plant compounds. Combined with estimated feeding rates of insects in sympatric bat species, our data suggest that gleaning bats are important predators of herbivorous insects and might be underestimated reducers of herbivory in the tropics.

The first fossil leaf insect: 47 million years of specialized cryptic morphology and behavior

“…Studies of the diet of extant insectivorous bats from the tropics have shown that gleaning bats can be important predators of herbivorous insects (26). Phasmids constituted only a small proportion of the diet of the observed bat species, but among the large prey stick insects were dominant.…”

“…It must have been caused by vigorous selection pressure by visually oriented predators. Common predators of adult phasmids are insectivorous birds (21), but also spiders, mantids, lizards, and bats (e.g., 20,[22][23][24][25][26] attacked large adult leaf insects. Leaf-mimicking orthopteroid insects like phaneropterines and pseudophyllinae (Orthoptera: Tettigoniidae) can constitute a large component of the diet of small neotropical monkeys (28).…”

A New Family of Large Omnivorous Bats (Mammalia, Chiroptera) from the Late Eocene of the Fayum Depression, Egypt, with Comments on Use of the Name “Eochiroptera”

“…In small animalivorous bats, the diet apparently usually consists mostly of insects and other arthropods (Norberg and Fenton, 1988;Kalka and Kalko, 2006, although also see Rex et al, 2010). As body size increases, some species with dilambdodont molar teeth often include small vertebrates in their diet.…”

Whistling in caterpillars (Amorpha juglandis, Bombycoidea): sound-producing mechanism and function

“…Caterpillar whistles also have significant energy in the ultrasound range and, thus, could be directed at gleaning bats and mice. There is evidence that bats eat large caterpillars (Kalka and Kalko, 2006;Wilson and Barclay, 2006), and mice are repelled by sounds produced by insects with similar sound frequencies [e.g. bee hissing (Kirchner and Röschard, 1999)].…”

“…Caterpillars are preyed upon heavily by a host of natural predators, including birds, wasps, shrews, mice, bats, snakes, frogs, lizards, ants, beetles and spiders (Holmes et al, 1979;Wagner, 2005;Kalka and Kalko, 2006). In response, they have developed a variety of anti-predator strategies, which have been studied extensively (e.g.…”