Interspecific and Intraspecific Partitioning of Foraging Times Among Three Tropical Bat Species in La Sierra Norte, Oaxaca, Mexico

Abstract

Bats play a vital role in many ecosystems by functioning as pollinators, seed dispersers, and pest-eaters. The greatest number of species can be found in the Neotropical zones, where it has been shown that an increase in the number of bat species corresponds to an increase in community diversity. One such place is the tropical rainforest of the Sierra Norte, located in Mexico’s southern state of Oaxaca (Fig. 1). To date, no studies here have investigated the behaviors that allow ecologically similar bat species to coexist in ways that minimize interference competition. I investigated the three most abundant bat species in the area: Dermanura tolteca, Sturnira ludovici, and Centurio senex, all of the family Phyllostomidae. These species are medium-sized frugivores (fruit-eating) known to roost in trees throughout Mexico, Central America, and northern parts of South America. I have investigated temporal partitioning as a possible mechanism of coexistence between these species. I hypothesize that there is a difference in times of foraging activity between the species (interspecific), and between members of different sexes, age-classes, and reproductive states within each species (intraspecific). Knowing the dynamic interactions of these groups will help us to better understand how members of a species utilize resources to facilitate their continued survival. It is imperative to study the very behaviors that allow bats to exist, as these species are crucial to the functioning and conservation of tropical ecosystems.