Skull Morphology, Bite Force, and Diet in Insectivorous Bats from Tropical Dry Forests in Colombia

Abstract

In Neotropical bats, studies on bite force have focused mainly on differences in trophic ecology, and little is known about whether factors other than body size generate interspecific differences in bite force amongst insectivorous bats and, consequently, in their diets. We tested if bite force is related to skull morphology and also to diet in an assemblage of Neotropical insectivorous bats from tropical dry forests in the inter-Andean central valley in Colombia. It is predicted that the preference of prey types among insectivorous species is based on bite force and cranial characteristics. We also evaluated whether skull morphology varies depending on the species and sex. Cranial measurements and correlations between morphological variation and bite force were examined for 10 insectivorous bat species. We calculated the size-independent mechanical advantage for the mandibular (jaw) lever system. In all species, bite force increased with length of the skull and the jaw more than other cranial measurements. Obligate insectivorous species were morphologically different from the omnivorous Noctilio albiventris, which feeds primarily on insects, but also consumes fish and fruits. Our results show that bite force and skull morphology are closely linked to diets in Neotropical insectivorous bats and, consequently, these traits are key to the interactions within the assemblage and with their prey.

Evolutionary pressures of aerial insectivory reflected in anurognathid pterosaurs

“…The mediolaterally wide skulls of anurognathids superficially resemble those seen in the Caprimulgidae. While there are chiropterans with varying skull widths, proportional widths vary less when compared among extant birds, and primary differences in proportional width are associated with bite strength, rather than prey capture strategies (Ramírez-Fráncel et al, 2021). For these reasons, cranial comparisons and associations with peak activity time were restricted to birds.…”

Acute exposure of fruit bats to low concentrations of heavy metals affects oxidative stress markers

“…Despite this, the risk assessment of contaminants in bats is developing and requires a specific approach for these animals (Hernández-Jerez et al, 2019). Bats also play a vital role in ecosystem services through pollination (bats pollinate 549 plant species), pest control (752 insect species are consumed by bats, including crop pests and disease vectors), and seed dispersal (Ramírez-Fráncel et al, 2022). The great fruit-eating bat (Artibeus lituratus) is an abundant species in the Neotropical region.…”